diff --git a/pkg/arvo/ted/test.hoon b/pkg/arvo/ted/test.hoon
index a25496fc2..43a81700c 100644
--- a/pkg/arvo/ted/test.hoon
+++ b/pkg/arvo/ted/test.hoon
@@ -66,7 +66,7 @@
   =/  fire-arm=nock
     ~|  [%failed-to-compile-test-arm name]
     q:(~(mint ut typ) p:!>(*tang) [%limb name])
-  [name |.(;;(tang .*(cor fire-arm)))]
+  [name |.(;;(tang ~>(%bout.[1 name] .*(cor fire-arm))))]
 ::  +has-test-prefix: does the arm define a test we should run?
 ::
 ++  has-test-prefix
diff --git a/pkg/urbit/include/c/motes.h b/pkg/urbit/include/c/motes.h
index cbb4850b2..807c80f78 100644
--- a/pkg/urbit/include/c/motes.h
+++ b/pkg/urbit/include/c/motes.h
@@ -112,6 +112,7 @@
 #   define c3__boot   c3_s4('b','o','o','t')
 #   define c3__born   c3_s4('b','o','r','n')
 #   define c3__both   c3_s4('b','o','t','h')
+#   define c3__bout   c3_s4('b','o','u','t')
 #   define c3__box    c3_s3('b','o','x')
 #   define c3__br     c3_s2('b','r')
 #   define c3__bran   c3_s4('b','r','a','n')
diff --git a/pkg/urbit/include/noun/trace.h b/pkg/urbit/include/noun/trace.h
index 80b7bc1e5..28b42151d 100644
--- a/pkg/urbit/include/noun/trace.h
+++ b/pkg/urbit/include/noun/trace.h
@@ -93,6 +93,12 @@
       void
       u3t_trace_close();
 
+    /* u3t_trace_time(): returns current time since system epoc,
+     * whatever it is per system, in microseconds.
+    */
+      c3_d
+      u3t_trace_time();
+
     /* u3t_nock_trace_push(): pushes a frame onto the trace stack;
     *  return yes if active push.
     */
diff --git a/pkg/urbit/noun/nock.c b/pkg/urbit/noun/nock.c
index bc41e5ddd..f2ec04e64 100644
--- a/pkg/urbit/noun/nock.c
+++ b/pkg/urbit/noun/nock.c
@@ -1004,8 +1004,8 @@ _n_emit(u3_noun *ops, u3_noun op)
 static c3_w _n_comp(u3_noun*, u3_noun, c3_o, c3_o);
 
 /* _n_bint(): hint-processing helper for _n_comp.
- *            hif: hint-formula (first part of 10). RETAIN.
- *            nef: next-formula (second part of 10). RETAIN.
+ *            hif: hint-formula (first part of 11). RETAIN.
+ *            nef: next-formula (second part of 11). RETAIN.
  */
 static c3_w
 _n_bint(u3_noun* ops, u3_noun hif, u3_noun nef, c3_o los_o, c3_o tel_o)
@@ -1021,18 +1021,22 @@ _n_bint(u3_noun* ops, u3_noun hif, u3_noun nef, c3_o los_o, c3_o tel_o)
         return _n_comp(ops, nef, los_o, tel_o);
       }
 
-      //  no currently recognized static hints
-      //
-      case u3_none: {
+      case c3__bout: {
         u3_noun fen = u3_nul;
         c3_w  nef_w = _n_comp(&fen, nef, los_o, tel_o);
+        // add appropriate hind opcode
+        ++nef_w; _n_emit(&fen, ( c3y == los_o ) ? HILL : HILK);
+        // skip over the cleanup opcode
+        ++nef_w; _n_emit(&fen, u3nc(SBIP, 1));
 
+        //  call hilt_fore
         //  HILB overflows to HILS
-        //
         ++tot_w; _n_emit(ops, u3nc(HILB, u3nc(u3k(hif), u3k(nef))));
-        ++tot_w; _n_emit(ops, u3nc(SBIN, nef_w + 1));
+        // if fore return c3n, skip fen
+        ++tot_w; _n_emit(ops, u3nc(SBIN, nef_w));
         tot_w += nef_w; _n_apen(ops, fen);
-        ++tot_w; _n_emit(ops, ( c3y == los_o ) ? HILL : HILK);
+        // post-skip cleanup opcode
+        ++tot_w; _n_emit(ops, ( c3y == los_o ) ? TOSS : SWAP);
       } break;
     }
   }
@@ -1052,19 +1056,24 @@ _n_bint(u3_noun* ops, u3_noun hif, u3_noun nef, c3_o los_o, c3_o tel_o)
             tot_w += _n_comp(ops, nef, los_o, tel_o);
           } break;
 
-          //  no currently recognized dynamic hints
-          //
-          case u3_none: {
+          case c3__bout: {
             u3_noun fen = u3_nul;
             c3_w  nef_w = _n_comp(&fen, nef, los_o, tel_o);
+            // add appropriate hind opcode
+            ++nef_w; _n_emit(&fen, ( c3y == los_o ) ? HINL : HINK);
+            // skip over the cleanup opcode
+            ++nef_w; _n_emit(&fen, u3nc(SBIP, 1));
 
+            // push clue
             tot_w += _n_comp(ops, hod, c3n, c3n);
+            //  call hint_fore
             //  HINB overflows to HINS
-            //
             ++tot_w; _n_emit(ops, u3nc(HINB, u3nc(u3k(zep), u3k(nef))));
-            ++tot_w; _n_emit(ops, u3nc(SBIN, nef_w + 1));
+            // if fore return c3n, skip fen
+            ++tot_w; _n_emit(ops, u3nc(SBIN, nef_w));
             tot_w += nef_w; _n_apen(ops, fen);
-            ++tot_w; _n_emit(ops, ( c3y == los_o ) ? HINL : HINK);
+            // post-skip cleanup opcode
+            ++tot_w; _n_emit(ops, ( c3y == los_o ) ? TOSS : SWAP);
           } break;
         }
       } break;
@@ -1677,18 +1686,25 @@ u3n_find(u3_noun key, u3_noun fol)
 }
 
 /* _n_hilt_fore(): literal (atomic) dynamic hint, before formula evaluation.
-**            lit: hint atom. TRANSFER
+**            hin: [hint-atom, formula]. TRANSFER
 **            bus: subject. RETAIN
-**            out: token for _n_hilt_hind();
-**                 conventionally, [lit] or [lit data]. ~ if unused.
+**            out: token for _n_hilt_hind(); convention:
+**                 [hint-atom] or [hint-atom data], ~ if unused.
 **
 **                 any hints herein must be whitelisted in _n_burn().
 */
 static c3_o
-_n_hilt_fore(u3_atom lit, u3_noun bus, u3_noun* out) // transfer, retain, n/a
+_n_hilt_fore(u3_noun hin, u3_noun bus, u3_noun* out)
 {
-  u3z(lit);
-  *out = u3_nul;
+  if ( c3__bout == u3h(hin) ) {
+    u3_atom now = u3i_chub(u3t_trace_time());
+    *out = u3i_cell(u3h(hin), now);
+  }
+  else {
+    *out = u3_nul;
+  }
+
+  u3z(hin);
   return c3y;
 }
 
@@ -1697,9 +1713,20 @@ _n_hilt_fore(u3_atom lit, u3_noun bus, u3_noun* out) // transfer, retain, n/a
 **            pro: product of formula evaluation. RETAIN
 */
 static void
-_n_hilt_hind(u3_noun tok, u3_noun pro)  // transfer, retain
+_n_hilt_hind(u3_noun tok, u3_noun pro)
 {
-  c3_assert( u3_nul == tok );
+  u3_noun p_tok, q_tok;
+  if ( (c3y == u3r_cell(tok, &p_tok, &q_tok)) && (c3__bout == p_tok) ) {
+    u3_atom delta = u3ka_sub(u3i_chub(u3t_trace_time()), u3k(q_tok));
+    c3_c    str_c[64];
+    snprintf(str_c, 63, "took %" PRIu64 "\xc2\xb5s", u3r_chub(0, delta) );
+    u3t_slog(u3nc(0, u3i_string(str_c)));
+    u3z(delta);
+  }
+  else {
+    c3_assert( u3_nul == tok );
+  }
+
   u3z(tok);
 }
 
@@ -1707,16 +1734,24 @@ _n_hilt_hind(u3_noun tok, u3_noun pro)  // transfer, retain
 **            hin: [hint-atom, formula]. TRANSFER
 **            bus: subject. RETAIN
 **            clu: product of the hint-formula. TRANSFER
-**                 also, token for _n_hint_hind();
-**                 conventionally, [hint-atom] or [hint-atom data]. ~ if unused.
+**                 also, token for _n_hilt_hind(); convention:
+**                 [hint-atom] or [hint-atom data], ~ if unused.
 **
 **                 any hints herein must be whitelisted in _n_burn().
 */
 static c3_o
 _n_hint_fore(u3_cell hin, u3_noun bus, u3_noun* clu)
 {
-  u3z(hin); u3z(*clu);
-  *clu = u3_nul;
+  if ( c3__bout == u3h(hin) ) {
+    u3_atom now = u3i_chub(u3t_trace_time());
+    *clu = u3i_trel(u3h(hin), *clu, now);
+  }
+  else {
+    u3z(*clu);
+    *clu = u3_nul;
+  }
+
+  u3z(hin);
   return c3y;
 }
 
@@ -1727,7 +1762,43 @@ _n_hint_fore(u3_cell hin, u3_noun bus, u3_noun* clu)
 static void
 _n_hint_hind(u3_noun tok, u3_noun pro)
 {
-  c3_assert( u3_nul == tok );
+  u3_noun p_tok, q_tok, r_tok;
+  if ( (c3y == u3r_trel(tok, &p_tok, &q_tok, &r_tok))
+      && (c3__bout == p_tok) )
+  {
+    // get the microseconds elapsed
+    u3_atom delta = u3ka_sub(u3i_chub(u3t_trace_time()), u3k(r_tok));
+
+    // unpack q_tok to get the priority integer and the tank
+    // p_q_tok is the priority, q_q_tok is the tank we will work with
+    u3_noun p_q_tok, q_q_tok;
+    c3_assert(c3y == u3r_cell(q_tok, &p_q_tok, &q_q_tok));
+
+    // format the timing report
+    c3_c str_c[64];
+    snprintf(str_c, 63, "took %" PRIu64 "\xc2\xb5s", u3r_chub(0, delta) );
+
+    // join the timing report with the original tank from q_q_tok like so:
+    // "q_q_tok: report"
+    // prepend the priority to form a cell of the same shape q_tok
+    // send this to ut3_slog so that it can be logged out
+    u3t_slog(
+      u3nc(
+        u3k(p_q_tok),
+        u3nt(
+          c3__rose,
+          u3nt(u3nt(':', ' ', u3_nul), u3_nul, u3_nul),
+          u3nt(u3k(q_q_tok), u3i_string(str_c), u3_nul)
+        )
+      )
+    );
+
+    u3z(delta);
+  }
+  else {
+    c3_assert( u3_nul == tok );
+  }
+
   u3z(tok);
 }
 
diff --git a/pkg/urbit/ur/hashcons.c b/pkg/urbit/ur/hashcons.c
index 4863ef6b7..a2dd691d7 100644
--- a/pkg/urbit/ur/hashcons.c
+++ b/pkg/urbit/ur/hashcons.c
@@ -937,7 +937,6 @@ struct ur_walk_fore_s {
   ur_root_t  *r;
   uint32_t prev;
   uint32_t size;
-  uint32_t fill;
   ur_nref  *top;
 };
 
@@ -950,7 +949,6 @@ ur_walk_fore_init_with(ur_root_t    *r,
   w->top = _oom("walk_fore", malloc(s_size * sizeof(*w->top)));
   w->prev = s_prev;
   w->size = s_size;
-  w->fill = 0;
   w->r    = r;
 
   return w;
@@ -969,45 +967,42 @@ ur_walk_fore_with(ur_walk_fore_t *w,
                   void       (*atom)(ur_root_t*, ur_nref, void*),
                   ur_bool_t  (*cell)(ur_root_t*, ur_nref, void*))
 {
-  ur_root_t *r = w->r;
-  ur_nref *don = w->top;
+  ur_root_t  *r = w->r;
+  uint32_t fill = 1;
 
-  w->top += ++w->fill;
   *w->top = ref;
 
-  while ( w->top != don ) {
+  do {
     //  visit atom, pop stack
     //
     if ( !ur_deep(ref) ) {
       atom(r, ref, v);
-      w->top--; w->fill--;
+      fill--;
     }
     //  visit cell, pop stack if false
     //
     else if ( !cell(r, ref, v) ) {
-      w->top--; w->fill--;
+      fill--;
     }
     //  push the tail, continue into the head
     //
     else {
-      *w->top = ur_tail(r, ref);
+      w->top[fill++] = ur_tail(r, ref);
 
       //  reallocate "stack" if full
       //
-      if ( w->size == w->fill ) {
+      if ( w->size == fill ) {
         uint32_t next = w->prev + w->size;
-        don     = _oom("walk_fore", realloc(don, next * sizeof(*don)));
-        w->top  = don + w->fill;
+        w->top  = _oom("walk_fore", realloc(w->top, next * sizeof(*w->top)));
         w->prev = w->size;
         w->size = next;
       }
 
-      w->top++; w->fill++;
-      *w->top = ur_head(r, ref);
+      w->top[fill] = ur_head(r, ref);
     }
 
-    ref = *w->top;
-  }
+    ref = w->top[fill];
+  } while ( fill );
 }
 
 void
diff --git a/pkg/urbit/ur/serial.c b/pkg/urbit/ur/serial.c
index 61eeca39c..2bdfa2f4b 100644
--- a/pkg/urbit/ur/serial.c
+++ b/pkg/urbit/ur/serial.c
@@ -134,7 +134,7 @@ void
 ur_jam_done(ur_jam_t *j)
 {
   ur_dict_free((ur_dict_t*)&j->dict);
-  free(j->w);
+  ur_walk_fore_done(j->w);
   free(j);
 }
 
diff --git a/pkg/urbit/vere/pier.c b/pkg/urbit/vere/pier.c
index db072f641..17be5776e 100644
--- a/pkg/urbit/vere/pier.c
+++ b/pkg/urbit/vere/pier.c
@@ -1114,7 +1114,7 @@ _pier_on_lord_play_bail(void* ptr_v, u3_info fon_u,
 
     //  dispose successful
     //
-    while ( tac_u->eve_d < eve_d ) {
+    while ( tac_u->eve_d <= eve_d ) {
       nex_u = tac_u->nex_u;
       las_l = tac_u->mug_l;
       u3_fact_free(tac_u);
diff --git a/pkg/urbit/worker/serf.c b/pkg/urbit/worker/serf.c
index 3e005a750..55cb3ad7d 100644
--- a/pkg/urbit/worker/serf.c
+++ b/pkg/urbit/worker/serf.c
@@ -751,16 +751,12 @@ _serf_play_list(u3_serf* sef_u, u3_noun eve)
 
       eve = u3t(eve);
     }
-    //  event succeeded, save and continue
+    //  event failed, stop and send trace
     //
     else {
-      u3_noun dud = u3k(u3t(gon));
-
       //  reset sent event counter
       //
-      sef_u->sen_d   = sef_u->dun_d;
-
-      u3z(gon);
+      sef_u->sen_d = sef_u->dun_d;
 
       //  XX reclaim on meme ?
       //
@@ -770,7 +766,7 @@ _serf_play_list(u3_serf* sef_u, u3_noun eve)
       u3z(vev);
       return u3nc(c3__bail, u3nt(u3i_chubs(1, &sef_u->dun_d),
                                  sef_u->mug_l,
-                                 dud));
+                                 gon));
     }
   }