I wrote a script called Knock Knock and John Cahill drew it. It is published in Something Wicked #5. Hope you enjoy it.
John Cahill also makes a second contribution to the same issue; Bad Static (written by Martin Hayes).
Unfortunately, there are some problems with FutureQuake Press website and you cannot purchase any of the issues from the website. However, you can via FutureQuake Press blog.
http://futurequakepress.blogspot.com/
If you are going to BICS this weekend (3rd-4th October, ThinkTank, Birmingham), you can also purchase those comics. The FutureQuake Press team will be setting up shop.