diff --git a/terranostra.lisp b/terranostra.lisp
index a194b61..cfc8ab3 100644
--- a/terranostra.lisp
+++ b/terranostra.lisp
@@ -1,4 +1,4 @@
-#!/usr/bin/clisp
+;#!/usr/bin/clisp
 ;;;;
 ;;;; Terra Nostra is a Minecraft-like survival game for the commandline.
 ;;;; 
@@ -8,6 +8,8 @@
 ;;(load "util.lisp") ;; I want to avoid using this if possible
 
 (defvar *world* NIL)
+(defconstant *directions* '(N NE E SE S SW W NW))
+
 
 (defstruct patch
 	(pos '(0 0)) ;position
@@ -15,6 +17,7 @@
 	(streams-in NIL)
 	(streams-out NIL))
 
+
 (defun init-matrix (size)
 	"Create a square matrix of empty patches"
 	(do ((y 0 (1+ y)) (world NIL) (row NIL NIL))
@@ -28,6 +31,11 @@
 	(unless (or (< x 0) (< y 0) (> x (length world)) (> y (length world)))
 		(nth x (nth y world))))
 
+(defun opposite-dir (dir)
+	"Return the direction opposite the input"
+	(let ((pos (position dir *directions*)))
+		(when pos (nth (rem (+ 4 pos) 8) *directions*))))
+
 (defun dir2patch (herex herey therex therey)
 	"Calculate the direction to a patch"
 	(cond ((> herex therex)
@@ -42,18 +50,28 @@
 			   ((< herey therey) 'N)
 			   (T NIL)))))
 
+(defun coordsindir (x y dir)
+	"Return the coordinates in the given direction"
+	(cond ((eq dir 'N) (list x (1- y)))
+		((eq dir 'NE) (list (1+ x) (1- y)))
+		((eq dir 'E) (list (1+ x) y))
+		((eq dir 'SE) (list (1+ x) (1+ y)))
+		((eq dir 'S) (list x (1+ y)))
+		((eq dir 'SW) (list (1- x) (1+ y)))
+		((eq dir 'W) (list (1- x) y))
+		((eq dir 'NW) (list (1- x) (1- y)))
+		((null dir) (list x y))
+		(T (error "~&Invalid direction ~S"))))
+
 (defun patchindir (x y dir &optional (world *world*))
 	"Return the patch in the given direction"
-	(cond ((eq dir 'N) (coord x (1- y) world))
-		((eq dir 'NE) (coord (1+ x) (1- y) world))
-		((eq dir 'E) (coord (1+ x) y world))
-		((eq dir 'SE) (coord (1+ x) (1+ y) world))
-		((eq dir 'S) (coord x (1+ y) world))
-		((eq dir 'SW) (coord (1- x) (1+ y) world))
-		((eq dir 'W) (coord (1- x) y world))
-		((eq dir 'NW) (coord (1- x) (1- y) world))
-		((null dir) (coord x y world))
-		(T (error "~&Invalid direction ~S"))))
+	(let* ((coords (coordsindir x y dir))
+			  (nextx (first coords)) (nexty (second coords)))
+		(coord nextx nexty world)))
+
+(defun neighbour (p dir &optional (world *world*))
+	"Return the neighbouring patch in this direction"
+	(patchindir (first (patch-pos p)) (second (patch-pos p)) dir world))
 
 (defun save-topography (file-name &optional (world *world*))
 	"Save the world topography as a csv file"
@@ -93,9 +111,7 @@
 (defun create-stream (x y world)
 	"Create a stream, starting at x/y"
 	;;TODO
-	(flet ((lowest-neighbour ())))
 	)
 
-
 ;; Initialize the random state (which would otherwise not be very random...)
 (setf *random-state* (make-random-state t))