diff --git a/library/lua/memscan.lua b/library/lua/memscan.lua
index ba3efd708..6796b3563 100644
--- a/library/lua/memscan.lua
+++ b/library/lua/memscan.lua
@@ -24,7 +24,7 @@ function CheckedArray:__len()
     return self.count
 end
 function CheckedArray:__index(idx)
-    if type(idx) == number then
+    if type(idx) == "number" then
         if idx >= self.count then
             error('Index out of bounds: '..tostring(idx))
         end
diff --git a/plugins/Dfusion/luafiles/embark/init.lua b/plugins/Dfusion/luafiles/embark/init.lua
index 529c2d1e5..aa8f2822d 100644
--- a/plugins/Dfusion/luafiles/embark/init.lua
+++ b/plugins/Dfusion/luafiles/embark/init.lua
@@ -1,3 +1,28 @@
+local dfu=require("dfusion")
+local ms=require("memscan")
+
+CustomEmbark=defclass(CustomEmbark,dfu.BinaryPlugin)
+CustomEmbark.ATTRS{filename="dfusion/embark/embark.o",name="CustomEmbark",race_caste_data=DEFAULT_NIL}
+function CustomEmbark:install()
+    local stoff=dfhack.internal.getAddress('start_dwarf_count')
+    if stoff==nil then
+        error("address for start_dwarf_count not found!")
+    end
+    local _,race_id_offset=df.sizeof(df.global.ui:_field("race_id"))
+    local needle={0x0f,0xb7,0x0d} --movzx,...
+    add_dword(needle,race_id_offset)    -- ...word ptr[]
+    local mem=ms.get_code_segment() 
+    local trg_offset=mem.uint8_t.find(needle,stoff)--maybe endoff=stoff+bignumber
+    if trg_offset==nil then
+        error("address for race_load not found")
+    end
+    needle={0x83,0xc8,0xff} -- or eax, 0xFF
+    local caste_offset=mem.uint8_t.find(needle,trg_offset)
+    if caste_offset==nil or caste_offset-stoff>1000 then
+        error("Caste change code not found or found too far!")
+    end
+    
+end
 function MakeTable(modpos,modsize,names)
 	count=0
 	castes={}
diff --git a/plugins/lua/dfusion.lua b/plugins/lua/dfusion.lua
new file mode 100644
index 000000000..06128d29b
--- /dev/null
+++ b/plugins/lua/dfusion.lua
@@ -0,0 +1,163 @@
+-- Stuff used by dfusion
+local _ENV = mkmodule('plugins.dfusion')
+
+local ms=require("memscan")
+
+local marker={0xDE,0xAD,0xBE,0xEF}
+patches={}
+-- A reversable binary patch
+BinaryPatch=defclass(BinaryPatch)
+BinaryPatch.ATTRS {pre_data=DEFAULT_NIL,data=DEFAULT_NIL,address=DEFAULT_NIL,name=DEFAULT_NIL}
+function BinaryPatch:init(args)
+    self.is_applied=false
+    if args.pre_data==nil or args.data==nil or args.address==nil or args.name==nil then
+        error("Invalid parameters to binary patch")
+    end
+    if patches[self.name]~=nil then
+        error("Patch already exist")
+    end
+    self.max_val=0
+    for k,v in pairs(args.pre_data) do
+        if type(k)~="number" then
+            error("non number key in pre_data")
+        end
+        if self.max_val<k then
+            self.max_val=k
+        end
+    end
+    for k,v in pairs(args.data) do
+        if type(k)~="number" then
+            error("non number key in data")
+        end
+        if args.pre_data[k]==nil then
+            error("can't edit without revert data")
+        end
+    end
+end
+function BinaryPatch:postinit(args)
+    patches[args.name]=self
+end
+function BinaryPatch:apply()
+    local arr=ms.CheckedArray.new('uint8_t',self.address,self.address+self.max_val)
+    for k,v in pairs(self.pre_data) do
+        if arr[k-1]~=v then
+            error(string.format("pre-data does not match expected:%x got:%x",v,arr[k-1]))
+        end
+    end
+    
+    local post_buf=df.new('uint8_t',self.max_val)
+    for k,v in pairs(self.pre_data) do
+        if self.data[k]==nil then
+            post_buf[k-1]=v
+        else
+            post_buf[k-1]=self.data[k]
+        end
+    end
+    local ret=dfhack.with_finalize(function() post_buf:delete() end,dfhack.internal.patchMemory,self.address,post_buf,self.max_val)
+    if not ret then
+        error("Patch application failed!")
+    end
+    self.is_applied=true
+    --[[
+    for k,v in pairs(self.data) do
+        arr[k]=v
+    end
+    ]]--
+end
+function BinaryPatch:remove(delete)
+    if delete==nil then
+        delete=true
+    end
+    if not self.is_applied then
+        error("can't remove BinaryPatch, not applied.")
+    end
+    local arr=ms.CheckedArray.new('uint8_t',self.address,self.address+self.max_val)
+    
+    local post_buf=df.new('uint8_t',self.max_val)
+    for k,v in pairs(self.pre_data) do
+            post_buf[k-1]=v
+    end
+    local ret=dfhack.with_finalize(function() post_buf:delete() end,dfhack.internal.patchMemory,self.address,post_buf,self.max_val)
+    if not ret then
+        error("Patch remove failed!")
+    end
+    self.is_applied=false
+    if delete then
+        patches[self.name]=nil
+    end
+    
+    --[[
+    for k,v in pairs(self.data) do
+        arr[k]=self.pre_data[k]
+    end --]]
+end
+
+function BinaryPatch:__gc()
+    if self.is_applied then
+        self:remove()
+    end
+end
+-- A binary hack (obj file) loader/manager
+-- has to have: a way to get offsets for marked areas (for post load modification) or some way to do that pre-load
+-- page managing (including excecute/write flags for DEP and the like)
+plugins=plugins or {}
+BinaryPlugin=defclass(BinaryPlugin)
+BinaryPlugin.ATTRS {filename=DEFAULT_NIL,reloc_table={},name=DEFAULT_NIL}
+function BinaryPlugin:init(args)
+    if args.name==nil then error("Not a valid plugin name!") end
+    if plugins[args.name]==nil then
+        plugins[args.name]=true
+    else
+        error("Trying to create a same plugin")
+    end
+    self.allocated_object={}
+    
+end
+function BinaryPlugin:postinit(args)
+    self:load()
+end
+function BinaryPlugin:allocate(name,typename,arrsize)
+    local trg
+    if df[typename]==nil then
+        trg=df.new(typename,arrsize)
+        self.allocated_object[name]=trg
+    else
+        trg=df[typename]:new(arrsize)
+        self.allocated_object[name]=trg
+    end
+    return trg
+end
+function BinaryPlugin:load()
+    local obj=loadObjectFile(self.filename)
+    self.data=df.reinterpret_cast("uint8_t",obj.data)
+    self.size=obj.data_size
+    for _,v in pairs(obj.symbols) do
+        if string.sub(v.name,1,5)=="mark_" then
+            local new_pos=self:find_marker(v.pos)
+            self.reloc_table[string.sub(v.name,6)]=new_pos
+        end
+    end
+end
+function BinaryPlugin:find_marker(start_pos)
+    local matched=0
+    for i=start_pos,self.size do
+        if self.data[i]==marker[4-matched] then
+            matched=matched+1
+            if matched == 4 then
+                return i-4
+            end
+        end
+    end
+end
+function BinaryPlugin:print_data()
+    local out=""
+    for i=0,self.size do
+        out=out..string.format(" %02x",self.data[i])
+        if math.modf(i,16)==15 then
+            print(out)
+            out=""
+        end
+    end
+    print(out)
+end
+return _ENV
\ No newline at end of file