diff --git a/base/sur/oct4/core.hook b/base/sur/oct4/core.hook
new file mode 100644
index 0000000000..27bb1905e3
--- /dev/null
+++ b/base/sur/oct4/core.hook
@@ -0,0 +1,20 @@
+::                                                      ::  ::
+::::  /hook/core/oct4/sur                               ::::::  dependencies
+  ::                                                    ::  ::
+/?    310                                               ::
+::                                                      ::  ::
+::::                                                    ::::::  semantics
+  ::                                                    ::  ::
+|%                                                      ::
+++  board   ,@                                          ::  one-player bitfield
+++  point   ,[x=@ y=@]                                  ::  coordinate
+++  stage   (pair (unit ship) (unit ship))              ::  players
+++  play    (each game tape)                            ::  update
+++  game                                                ::  game state
+            $:  who=?                                   ::  whose turn
+                sag=stage                               ::  who's playing
+                aud=(map ship ,@ud)                     ::  who's watching
+                box=board                               ::  X board
+                boo=board                               ::  O board
+            ==                                          ::
+--