diff --git a/chapter2.lisp b/chapter2.lisp
index 7a67888..86d8c53 100644
--- a/chapter2.lisp
+++ b/chapter2.lisp
@@ -155,3 +155,9 @@ and upper bound."
 
 (defvar list-3 (list 1 (list 2 (list 3 (list 4 (list 5 (list 6 7)))))))
 (defun pick-7-list-3 () (cadr (cadr (cadr (cadr (cadr (cadr list-3)))))))
+
+;; Exercise 2.27
+(defun deep-reverse (l)
+  (if (null l)
+      ()
+      (append (deep-reverse (cdr l)) (list (car l)))))