diff --git a/pkg/noun/v2/allocate.h b/pkg/noun/v2/allocate.h
index 48ef44267f..bbce4ad121 100644
--- a/pkg/noun/v2/allocate.h
+++ b/pkg/noun/v2/allocate.h
@@ -8,7 +8,6 @@
 
   /**  Aliases.
   **/
-#     define u3R_v2              u3R
 #     define u3a_v2_botox        u3a_botox
 #     define u3a_v2_box          u3a_box
 #     define u3a_v2_cell         u3a_cell
@@ -26,7 +25,7 @@
 #     define u3a_v2_rewrite      u3a_rewrite
 #     define u3a_v2_rewrite_ptr  u3a_rewrite_ptr
 #     define u3a_v2_rewritten    u3a_rewritten
-#     define u3a_v2_road         u3a_road
+#     define u3a_v2_road         u3a_v2_road
 #     define u3a_v2_wfree        u3a_wfree
 #     define u3a_v2_to_off       u3a_to_off
 #     define u3a_v2_to_ptr       u3a_to_ptr
@@ -34,6 +33,75 @@
 #     define u3a_v2_to_pug       u3a_to_pug
 #     define u3a_v2_to_pom       u3a_to_pom
 
+  /**  Data structures.
+  **/
+    /* u3a_v2_road: contiguous allocation and execution context.
+    */
+      typedef struct _u3a_v2_road {
+        u3p(struct _u3a_v2_road) par_p;          //  parent road
+        u3p(struct _u3a_v2_road) kid_p;          //  child road list
+        u3p(struct _u3a_v2_road) nex_p;          //  sibling road
+
+        u3p(c3_w) cap_p;                      //  top of transient region
+        u3p(c3_w) hat_p;                      //  top of durable region
+        u3p(c3_w) mat_p;                      //  bottom of transient region
+        u3p(c3_w) rut_p;                      //  bottom of durable region
+        u3p(c3_w) ear_p;                      //  original cap if kid is live
+
+        c3_w fut_w[32];                       //  futureproof buffer
+
+        struct {                              //  escape buffer
+          union {
+            jmp_buf buf;
+            c3_w buf_w[256];                  //  futureproofing
+          };
+        } esc;
+
+        struct {                              //  miscellaneous config
+          c3_w fag_w;                         //  flag bits
+        } how;                                //
+
+        struct {                              //  allocation pools
+          u3p(u3a_fbox) fre_p[u3a_fbox_no];   //  heap by node size log
+          u3p(u3a_fbox) cel_p;                //  custom cell allocator
+          c3_w fre_w;                         //  number of free words
+          c3_w max_w;                         //  maximum allocated
+        } all;
+
+        u3a_jets jed;                         //  jet dashboard
+
+        struct {                              // bytecode state
+          u3p(u3h_root) har_p;                // formula->post of bytecode
+        } byc;
+
+        struct {                              //  namespace
+          u3_noun gul;                        //  (list $+(* (unit (unit)))) now
+        } ski;
+
+        struct {                              //  trace stack
+          u3_noun tax;                        //  (list ,*)
+          u3_noun mer;                        //  emergency buffer to release
+        } bug;
+
+        struct {                              //  profile stack
+          c3_d    nox_d;                      //  nock steps
+          c3_d    cel_d;                      //  cell allocations
+          u3_noun don;                        //  (list batt)
+          u3_noun trace;                      //  (list trace)
+          u3_noun day;                        //  doss, only in u3H (moveme)
+        } pro;
+
+        struct {                              //  memoization
+          u3p(u3h_root) har_p;                //  (map (pair term noun) noun)
+        } cax;
+      } u3a_v2_road;
+
+  /**  Globals.
+  **/
+      /// Current road (thread-local).
+      extern u3a_v2_road* u3a_v2_Road;
+#       define u3R_v2  u3a_v2_Road
+
   /**  Functions.
   **/
     /**  Allocation.
diff --git a/pkg/noun/v2/vortex.h b/pkg/noun/v2/vortex.h
index dd002eb9e5..d9fc8fcbbb 100644
--- a/pkg/noun/v2/vortex.h
+++ b/pkg/noun/v2/vortex.h
@@ -5,11 +5,29 @@
 
 #include "pkg/noun/vortex.h"
 
+#include "pkg/noun/v2/allocate.h"
+#include "pkg/noun/version.h"
+
   /**  Aliases.
   **/
-#     define     u3H_v2       u3H
 #     define     u3v_v2_arvo  u3v_arvo
-#     define     u3v_v2_home  u3v_home
+
+  /**  Data structures.
+  **/
+    /* u3v_v2_home: all internal (within image) state.
+    **       NB: version must be last for discriminability in north road
+    */
+      typedef struct _u3v_v2_home {
+        u3a_v2_road    rod_u;                //  storage state
+        u3v_v2_arvo    arv_u;                //  arvo state
+        u3v_version    ver_w;                //  version number
+      } u3v_v2_home;
+
+  /**  Globals.
+  **/
+      /// Arvo internal state.
+      extern u3v_v2_home* u3v_v2_Home;
+#       define u3H_v2  u3v_v2_Home
 
   /**  Functions.
   **/