Whizz bang, it's Bonfire Night weekend. Scour our round of up of flaming events for the free ones - watch out for paid and ticketed events. Away from the sparklers and burning pyres, there's plenty more to do for not a lot of dosh.
Friday: It's the opening of Dalston Underground Studios - Ten Year Anniversary exhibition. Current studio artists have invited previous studio-holders to exhibit alongside them. 6pm-11pm. The Boys Hall, Dalston, 68 Boleyn Road, N16 8JG. To attend, email your full name to firstname.lastname@example.org.
The National Gallery is open late till 9pm.
Saturday: The Grant Museum may still be shut but its Festival of Geology goes ahead. Handle fossils, marvel at minerals, try gem-panning and catch a talk on whale eating sharks. Free, 10.30am-4.30pm. The Wilkins Building at UCL, WC1E 6BT
Go hula hooping at the Royal Festival Hall. 1-5pm, free.
Strictly devotees, get your social dance practice in at the Croydon Clocktower Tea Dance at 5pm. £6 but if you live or work in Croydon, it's just £3.
Late at the Barbican is all about Cosplay tonight, inspired by their Japan season. Expect some amazing costumes and learn how to customise your own. There will be fashion shows, video games, djs and music and it's all free. Open 6.15pm till 1am at Barbican Centre, EC2Y 8DS.
The "reticent stand up comedy show Unweaving Rainbows at Etcetera Theatre is just £5 a ticket. 9.30pm, Camden, NW1 7BU
Sunday: Help Thames21 clean up Fulham's foreshore SW6, between 9.15-11.45am.
It's the last day of the free Broadwater Farm estate exhibition in N17.
Find out about Vienna with a seven-minute short film projected onto 25 Store St South Crescent, WC1E 7BL which brings the old and new city together in "a jaw-dropping 3D light spectacular". On loop between 8-10pm, free.
The Secret Chiefs meet at the Devereux pub, WC2R 3JJ to hear a talk on 'Spellcasting, Charms and Elves (we misread that as Elvis, temporarily) - Lives Of Common People In Anglo-Saxon Times' starting at 8.30pm. All welcome, £2.
Tuesday: Tim Key's doing a free comedy gig at Rough Trade East E1 6QL at 7pm. Pick up a wristband an hour before showtime.
Wednesday: The European Recycling Party throws a party at Punk Soho, 14 Soho St W1D 3DN. Free admission when you bring any used handheld item with a plug or a battery to be recycled. 8pm till late.
What have we missed? Shout it out in the comments.