Things to do
TOP SECRET: Sssh... don't tell anyone. Science Museum launches a Top Secret new exhibition today, looking at the world of codebreaking, ciphers and secret communications. See declassified files going back over a century, find out about gadgets that have been used to hide secrets, and learn more about Alan Turing and the codebreakers of Bletchley Park. Science Museum (South Kensington), free, book ahead, 10 July-23 February
CURATOR TOUR: Get a closer look at the current Art of Persuasion exhibition on this curator tour. The hour-long event offers an insight into the work of war poster artist Abram Games, whose work continues to influence designers today. National Army Museum (Chelsea), £10.50, book ahead, 11am
LILY ALLEN: Singer-songwriter Lily Allen appears at Waterstones to meet fans and sign copies of her memoir My Thoughts Exactly. The event celebrates its paperback release, and you're advised to get there early to get a place in the queue. Waterstones Piccadilly, free entry, just turn up, 12.30pm-2pm
PLANE TREES: The London Plane Tree Conference — chaired by Londonist Editor-at-Large Matt Brown — celebrates London's unique, green landscape. Throughout the afternoon hear from speakers including Paul Wood, author of London’s Street Trees, and Barbara Milne, City of Westminster and London Tree Officers Association, about what can be done to protect the landscape for future generations. City Hall, £10, book ahead, 2pm-5pm
PIZZA PARTY: Radio Alice Pizzeria celebrates the launch of its new Canary Wharf branch with a pizza party. Two DJs offer the soundtrack while 3,000 slices of pizza are given away free. Radio Alice (Canary Wharf), free entry, book ahead, 5pm-8pm
CRAZY RICH ASIANS: Settle down for a free, open-air screening of Crazy Rich Asians next to the canal in Paddington. Deckchairs and blankets are available on a first come, first served basis, and plenty of nearby restaurants sell refreshments. Merchant Square (Paddington), free, just turn up, 5.30pm-7.30pm
LONDON'S AIR AMBULANCE: London's Air Ambulance has been saving lives for 30 years. Mark the anniversary with a free lecture about what it takes to save critically injured people here in the capital, and hear about some of the cutting-edge technology being used from the east London base. Centre of the Cell (Whitechapel), free, book ahead, 6pm-7.30pm
TRAVEL WRITING: Fancy yourself as a travel writer? Jonathan Lorie's been in the trade for more than 20 years, and has just written a book sharing his tips and tricks. Hear from the man himself and have a go yourself in this interactive seminar. Citizen M Hotel (Bankside), £4, book ahead, 6.30pm-8.30pm
EDINBURGH PREVIEW: Stand-up comedian George Egg — known for cooking live on stage — offers a preview of his new show Movable Feast before he performs it in Edinburgh. See him demonstrate how to cook with an engine, procure items from the train buffet trolley and turn unexpected roadworks into a picnic. The Bill Murray (Islington), £5, book ahead, 6.45pm-7.45pm
DRAG BINGO: Wednesday night is drag bingo night at Queen of Hoxton. It's like regular bingo, but much livelier, with drag queens calling out the numbers, in a night of balls and wigs. Queen of Hoxton, £1, book ahead, 7pm-11.59pm
Tube ponderings with Barry Heck
Our resident tube fancier dishes out daily thoughts on the London Underground.
Following on from yesterday's musings, the one place where you CAN still get a drink beside a tube platform is at Kew Gardens station. Here, the lovely Tap on the Line pub (a Fuller's house) has large glass windows facing onto the Underground/Overground platforms. I seem to recall that it was once possible to walk directly onto the platform from the pub but, these days, one has to circle round outside and go through the barriers. Follow Barry on Twitter @HeckTube.
Good cause of the day
The Joint Council for the Welfare of Immigrants hosts a fundraising summer party, celebrating its successes of the past year and raising further funds to protect the legal rights of immigrants. Food is included in the ticket price, with drinks available to buy at the bar, plus there's a raffle, live music, and outdoor play area for kids. Find out more and book tickets.