I have been reliably informed that tickets are selling quick for this thing, so if you haven't booked yours yet, you can via these links:

http://billetto.co.uk/shhhfestival-london
and here: http://www.wegottickets.com/thelocal/event/267199
(Apparently Billetto has lower booking fee)

Vital Info:
HEATH STREET BAPTIST CHURCH, HAMPSTEAD
SAT 24TH MAY, 2014 Doors 12.00pm
We're on at 2.30 upstairs

See you there :)