diff --git a/luprex/cpp/core/drivenengine.cpp b/luprex/cpp/core/drivenengine.cpp
index acc383d6..eddaa93c 100644
--- a/luprex/cpp/core/drivenengine.cpp
+++ b/luprex/cpp/core/drivenengine.cpp
@@ -486,8 +486,8 @@ void DrivenEngine::drv_call_event_update(double clock) {
     event_update();
 }
 
-void DrivenEngine::drv_invoke_player(int64_t place, uint32_t datapklen, const char *datapk) {
-    Invocation *inv = new Invocation(Invocation::KIND_PLAYER, visible_actor_id_, place, std::string_view(datapk, datapklen));
+void DrivenEngine::drv_invoke_engio(int64_t place, uint32_t datapklen, const char *datapk) {
+    Invocation *inv = new Invocation(Invocation::KIND_ENGIO, visible_actor_id_, place, std::string_view(datapk, datapklen));
     queued_invocations_.emplace_back(inv);
 }
 
@@ -826,7 +826,7 @@ static void replay_invoke_event_update(EngineWrapper *w) {
 ////////////////////////
 
 
-void play_invoke_player(EngineWrapper *w, int64_t place, uint32_t datapklen, const char *datapk) {
+void play_invoke_engio(EngineWrapper *w, int64_t place, uint32_t datapklen, const char *datapk) {
     assert(w->rlog == nullptr);
     if (w->wlog != nullptr) {
         w->wlog->write_cmd_hash(PLAY_INVOKE_PLAYER, eng::memhash());
@@ -835,17 +835,17 @@ void play_invoke_player(EngineWrapper *w, int64_t place, uint32_t datapklen, con
         w->wlog->flush();
     }
 
-    w->engine->drv_invoke_player(place, datapklen, datapk);
+    w->engine->drv_invoke_engio(place, datapklen, datapk);
 }
 
-void replay_invoke_player(EngineWrapper *w) {
+void replay_invoke_engio(EngineWrapper *w) {
     int64_t place = w->rlog->read_int64();
     std::string srcpack = w->rlog->read_string();
     if (!w->rlog->good()) {
-        return reset_wrapper(w, "replay log corrupt in replay_invoke_player");
+        return reset_wrapper(w, "replay log corrupt in replay_invoke_engio");
     }
 
-    w->engine->drv_invoke_player(place, srcpack.size(), srcpack.c_str());
+    w->engine->drv_invoke_engio(place, srcpack.size(), srcpack.c_str());
 }
 
 
@@ -1029,7 +1029,7 @@ static void init_engine_wrapper_helper(EngineWrapper *w) {
     w->play_notify_close = play_notify_close;
     w->play_notify_accept = play_notify_accept;
     w->play_invoke_event_update = play_invoke_event_update;
-    w->play_invoke_player = play_invoke_player;
+    w->play_invoke_engio = play_invoke_engio;
     w->play_invoke_choose = play_invoke_choose;
     w->play_invoke_lua_source = play_invoke_lua_source;
 
diff --git a/luprex/cpp/core/drivenengine.hpp b/luprex/cpp/core/drivenengine.hpp
index 4cf13cfc..d9c7a4a1 100644
--- a/luprex/cpp/core/drivenengine.hpp
+++ b/luprex/cpp/core/drivenengine.hpp
@@ -293,7 +293,7 @@ public:
     void drv_notify_close(uint32_t chid, uint32_t len, const char *data);
     uint32_t drv_notify_accept(uint32_t port);
     void drv_call_event_update(double clock);
-    void drv_invoke_player(int64_t place, uint32_t datapklen, const char *datapk);
+    void drv_invoke_engio(int64_t place, uint32_t datapklen, const char *datapk);
     void drv_invoke_choose(int64_t place, uint32_t datapklen, const char *datapk);
     void drv_invoke_lua_source(uint32_t srcpklen, const char *srcpk);
 
diff --git a/luprex/cpp/core/enginewrapper.hpp b/luprex/cpp/core/enginewrapper.hpp
index 42b42398..aac291c0 100644
--- a/luprex/cpp/core/enginewrapper.hpp
+++ b/luprex/cpp/core/enginewrapper.hpp
@@ -197,12 +197,12 @@ struct EngineWrapper {
     //
     void (*play_invoke_event_update)(EngineWrapper *w, double clock);
 
-    // Send an invoke/KIND_PLAYER
+    // Send an invoke/KIND_ENGIO
     //
     // This is the main pathway for the graphics engine to control the player
     // character.  
     //
-    void (*play_invoke_player)(EngineWrapper *w, int64_t place, uint32_t datapklen, const char *datapk);
+    void (*play_invoke_engio)(EngineWrapper *w, int64_t place, uint32_t datapklen, const char *datapk);
 
     // Send an invoke/KIND_CHOOSE
     //
diff --git a/luprex/cpp/core/invocation.hpp b/luprex/cpp/core/invocation.hpp
index e372610b..07303f13 100644
--- a/luprex/cpp/core/invocation.hpp
+++ b/luprex/cpp/core/invocation.hpp
@@ -48,7 +48,7 @@ public:
     enum Kind {
         KIND_INVALID,
         KIND_CHOOSE,
-        KIND_PLAYER,
+        KIND_ENGIO,
         KIND_LUA,
         KIND_FLUSH_PRINTS,
         KIND_TICK,
diff --git a/luprex/cpp/core/lpxclient.cpp b/luprex/cpp/core/lpxclient.cpp
index 3683fff3..1dfdfd58 100644
--- a/luprex/cpp/core/lpxclient.cpp
+++ b/luprex/cpp/core/lpxclient.cpp
@@ -141,11 +141,7 @@ public:
     }
 
     void do_work_command(const util::StringVec &words) {
-        int reps = 10000;
-        for (int i = 0; i < reps; i++) {
-            world_to_synchronous();
-            world_to_asynchronous();
-        }
+        // The 'work' command is a stub for sticking temporary debugging code in here.
     }
 
     void do_quit_command(const util::StringVec &words) {
diff --git a/luprex/cpp/core/world-core.cpp b/luprex/cpp/core/world-core.cpp
index 9b96d14e..93e4d2d2 100644
--- a/luprex/cpp/core/world-core.cpp
+++ b/luprex/cpp/core/world-core.cpp
@@ -569,8 +569,8 @@ void World::invoke(const Invocation &inv) {
     case Invocation::KIND_CHOOSE:
         invoke_choose(inv.actor(), inv.place(), inv.datapack());
         break;
-    case Invocation::KIND_PLAYER:
-        invoke_player(inv.actor(), inv.place(), inv.datapack());
+    case Invocation::KIND_ENGIO:
+        invoke_engio(inv.actor(), inv.place(), inv.datapack());
         break;
     case Invocation::KIND_LUA:
         invoke_lua(inv.actor(), inv.place(), inv.datapack());
@@ -769,7 +769,7 @@ void World::invoke_choose(int64_t actor_id, int64_t place_id, std::string_view d
     assert(stack_is_clear());
 }
 
-void World::invoke_player(int64_t actor_id, int64_t place_id, std::string_view datapack) {
+void World::invoke_engio(int64_t actor_id, int64_t place_id, std::string_view datapack) {
     assert(stack_is_clear());
 
     // Get the actor and place.  Make sure both exist.
@@ -793,7 +793,7 @@ void World::invoke_player(int64_t actor_id, int64_t place_id, std::string_view d
     } catch (const StreamException &ex) {
         return;
     }
-    if (sv::is_lua_id(funcname)) {
+    if (!sv::is_lua_id(funcname)) {
         return;
     }
 
@@ -812,7 +812,7 @@ void World::invoke_player(int64_t actor_id, int64_t place_id, std::string_view d
         }
 
         // Get the closure (playerinvoke.funcname).
-        eng::string err = LS.getclass(playercb, "playerinvoke");
+        eng::string err = LS.getclass(playercb, "engio");
         if ((!err.empty()) || (!LS.istable(playercb))) {
             return;
         }
@@ -829,7 +829,30 @@ void World::invoke_player(int64_t actor_id, int64_t place_id, std::string_view d
         lua_pushvalue(L, place.index());
 
         // Push any additional args from the datapack.
-        // TODO: IMPLEMENT ME.
+        try {
+            while (!datasb.empty()) {
+                SimpleDynamicTag type = datasb.read_simple_dynamic_tag();
+                switch (type) {
+                    case SimpleDynamicTag::NUMBER: {
+                        lua_pushnumber(L, datasb.read_double());
+                        break;
+                    }
+                    case SimpleDynamicTag::BOOLEAN: {
+                        lua_pushboolean(L, datasb.read_bool() ? 1:0);
+                        break;
+                    }
+                    case SimpleDynamicTag::STRING: {
+                        std::string_view s = datasb.read_string_view();
+                        lua_pushlstring(L, s.data(), s.size());
+                        break;
+                    }
+                    default: return;
+                }
+                nargs++;
+            }
+        } catch (const StreamException &exc) {
+            return;
+        }
 
         // Transfer all arguments to the new thread.
         lua_xmove(L, CO, nargs);
diff --git a/luprex/cpp/core/world.hpp b/luprex/cpp/core/world.hpp
index 3d077158..3f5d8030 100644
--- a/luprex/cpp/core/world.hpp
+++ b/luprex/cpp/core/world.hpp
@@ -355,7 +355,7 @@ private:
 
     // Invoke a player method, used by the graphics engine to control the player.
     //
-    void invoke_player(int64_t actor_id, int64_t place_id, std::string_view datapack);
+    void invoke_engio(int64_t actor_id, int64_t place_id, std::string_view datapack);
 
     // Invoke a lua string.
     //
diff --git a/luprex/lua/login.lua b/luprex/lua/login.lua
index 0618775f..08197eae 100644
--- a/luprex/lua/login.lua
+++ b/luprex/lua/login.lua
@@ -49,4 +49,9 @@ function gosomewhere()
 
 function mkt()
     return tangible.build{class="login", animstate={plane="somewhere", xyz={1,2,3}}}
-    end
\ No newline at end of file
+    end
+
+makeclass("engio")
+function engio.myfunction(actor, place, a, b, c)
+    print("Myfunction actor=", actor," place=", place, " a=", a, " b=", b, " c=", c)
+    end