London is currently a very hot, sticky and unpleasant place to be. As a result, sensible folk will be grabbing themselves cold drinks and sitting in the shade tomorrow. You on the other hand have the opportunity to stick two fingers up at convention.
Yes chums, throw away your T-shirts and shorts and reach for your takeaway stained anoraks, because tomorrow is mart day! That's right, mart day! Your chance to do battle with a bunch of fat sweaty fuckers over boxes of yellowing old comics in an unventilated room. HUZZAH!
If you need directions they're HERE.
Alternatively, get off at Russell Square tube and follow the smell.