diff --git a/rust/ares/src/jets/hot.rs b/rust/ares/src/jets/hot.rs
index fb366f6..4b95012 100644
--- a/rust/ares/src/jets/hot.rs
+++ b/rust/ares/src/jets/hot.rs
@@ -2,7 +2,7 @@ use crate::jets::*;
 use crate::noun::{Atom, DirectAtom, IndirectAtom, Noun, D, T};
 use ares_macros::tas;
 use either::Either::{self, Left, Right};
-use std::ptr::null_mut;
+use std::ptr::{copy_nonoverlapping, null_mut};
 
 /** Root for Hoon %k.139
  */
@@ -826,3 +826,27 @@ struct HotMem {
     jet: Jet,
     next: Hot,
 }
+
+impl Preserve for Hot {
+    unsafe fn preserve(&mut self, stack: &mut NockStack) {
+        let mut it = self;
+        while !it.0.is_null() && !stack.is_in_frame(it.0) {
+            let dest_mem = stack.struct_alloc_in_previous_frame(1);
+            copy_nonoverlapping(it.0, dest_mem, 1);
+            it.0 = dest_mem;
+            (*it.0).a_path.preserve(stack);
+            (*it.0).axis.preserve(stack);
+            it = &mut (*it.0).next;
+        }
+    }
+
+    unsafe fn assert_in_stack(&self, stack: &NockStack) {
+        let mut it = self;
+        while !it.0.is_null() {
+            stack.assert_struct_is_in(it.0, 1);
+            (*it.0).a_path.assert_in_stack(stack);
+            (*it.0).axis.assert_in_stack(stack);
+            it = &mut (*it.0).next;
+        }
+    }
+}
diff --git a/rust/ares/src/mem.rs b/rust/ares/src/mem.rs
index b33b8b6..9a6352a 100644
--- a/rust/ares/src/mem.rs
+++ b/rust/ares/src/mem.rs
@@ -74,7 +74,7 @@ impl NockStack {
         unsafe {
             *frame_pointer.sub(FRAME + 1) = ptr::null::<u64>() as u64; // "frame pointer" from "previous" frame
             *frame_pointer.sub(STACK + 1) = ptr::null::<u64>() as u64; // "stack pointer" from "previous" frame
-            *frame_pointer.sub(ALLOC + 1) = ptr::null::<u64>() as u64; // "alloc pointer" from "previous" frame
+            *frame_pointer.sub(ALLOC + 1) = start as u64; // "alloc pointer" from "previous" frame
         };
         NockStack {
             start,
@@ -87,6 +87,42 @@ impl NockStack {
         }
     }
 
+    /** Resets the NockStack but flipping the top-frame polarity and unsetting PC. Sets the alloc
+     * pointer to the "previous" alloc pointer stored in the top frame to keep things "preserved"
+     * from the top frame. This allows us to do a copying GC on the top frame without erroneously
+     * "popping" the top frame.
+     */
+    pub unsafe fn flip_top_frame(&mut self, top_slots: usize) {
+        // Assert that we are at the top
+        assert!((*self.prev_frame_pointer_pointer()).is_null());
+        assert!((*self.prev_stack_pointer_pointer()).is_null());
+        let new_alloc_pointer = *(self.prev_alloc_pointer_pointer());
+
+        if self.is_west() {
+            // new top frame will be east
+            let new_frame_pointer = self.start.add(self.size).sub(RESERVED + top_slots) as *mut u64;
+            *new_frame_pointer.add(FRAME) = ptr::null::<u64>() as u64;
+            *new_frame_pointer.add(STACK) = ptr::null::<u64>() as u64;
+            *new_frame_pointer.add(ALLOC) = self.start as u64;
+            self.frame_pointer = new_frame_pointer;
+            self.stack_pointer = new_frame_pointer;
+            self.alloc_pointer = new_alloc_pointer;
+            self.pc = false;
+            assert!(!self.is_west());
+        } else {
+            // new top frame will be west
+            let new_frame_pointer = self.start.add(RESERVED + top_slots) as *mut u64;
+            *new_frame_pointer.sub(FRAME + 1) = ptr::null::<u64>() as u64;
+            *new_frame_pointer.sub(STACK + 1) = ptr::null::<u64>() as u64;
+            *new_frame_pointer.sub(ALLOC + 1) = self.start as u64;
+            self.frame_pointer = new_frame_pointer;
+            self.stack_pointer = new_frame_pointer;
+            self.alloc_pointer = new_alloc_pointer;
+            self.pc = false;
+            assert!(self.is_west());
+        }
+    }
+
     /** Resets the NockStack. */
     pub fn reset(&mut self, top_slots: usize) {
         self.frame_pointer = unsafe { self.start.add(RESERVED + top_slots) } as *mut u64;
@@ -96,7 +132,7 @@ impl NockStack {
         unsafe {
             *self.frame_pointer.sub(FRAME + 1) = ptr::null::<u64>() as u64; // "frame pointer" from "previous" frame
             *self.frame_pointer.sub(STACK + 1) = ptr::null::<u64>() as u64; // "stack pointer" from "previous" frame
-            *self.frame_pointer.sub(ALLOC + 1) = ptr::null::<u64>() as u64; // "alloc pointer" from "previous" frame
+            *self.frame_pointer.sub(ALLOC + 1) = self.start as u64; // "alloc pointer" from "previous" frame
         };
     }
 
diff --git a/rust/ares/src/serf.rs b/rust/ares/src/serf.rs
index bfe4e27..6fff0be 100644
--- a/rust/ares/src/serf.rs
+++ b/rust/ares/src/serf.rs
@@ -355,7 +355,6 @@ pub fn serf(constant_hot_state: &[HotEntry]) -> io::Result<()> {
         // Reset the local cache and scry handler stack
         context.nock_context.cache = Hamt::<Noun>::new(&mut context.nock_context.stack);
         context.nock_context.scry_stack = D(0);
-        context.nock_context.stack.frame_push(0);
 
         let tag = slot(writ, 2)?.as_direct().unwrap();
         match tag.data() {
@@ -400,13 +399,15 @@ pub fn serf(constant_hot_state: &[HotEntry]) -> io::Result<()> {
         clear_interrupt();
 
         // Persist data that should survive between events
-        //  XX: Such data should go in the PMA once that's available
+        //  XX: Such data should go in the PMA once that's available, except
+        //  the warm and hot state which should survive between events but not interpreter runs
         unsafe {
             let stack = &mut context.nock_context.stack;
             stack.preserve(&mut context.arvo);
             stack.preserve(&mut context.nock_context.cold);
             stack.preserve(&mut context.nock_context.warm);
-            stack.frame_pop();
+            stack.preserve(&mut context.nock_context.hot);
+            stack.flip_top_frame(0);
         }
     }