Hi
Where abouts in London is your friend staying (since its quite a big place and can take time to get across) and is your friend looking for a club or a good club (i.e. would be prepared to travel further to go to a good club)?
The two best clubs in London for epee are LTFC (
http://www.londonthamesfencingclub.com/) and Haverstock (
http://freespace.virgin.net/peter.hfc/). The former is in South West London, the latter is more North London. I am pretty sure that both would welcome visitors with open arms - like fencing clubs the world over, British clubs tend to be a friendly bunch...
Boo