Religion, climate chaos, mass extinction, and the AI apocalypse were among the big ideas explored on Hampstead Heath over a sunny weekend.
But the people behind HowTheLightGetsIn ensured the two days weren't all about the end of the world as we know it.
Sure, it's one of few festivals where you will spot huge queues for a talk on particle physics or a debate on Nietzsche versus Dostoevsky.
But the beauty of having a broad church of events and ideas, is there's something for everyone in a day which opens with a 9.30am philosophy breakfast unpacking pseudo science and impartial news, and closes at 11pm with comedy and live music.
In between there are children's workshops, book signings and big table four course feasts in the the circle of tents in the grounds of Kenwood, with names like Alastair Campbell, Ruby Wax and David Baddiel giving talks across the weekend.
In truth, the festival is a relaxed but stimulating affair, there are nice loos, no real queues, and plenty of spots like the tea and prosecco tent, or the woodburner for a chilled sit down.
On Saturday afternoon I caught ex Guardian editor Alan Rusbridger talking about the decline of trust in journalistic integrity, a fascinating lecture on blurred sexual boundaries and patriarchy in the animal kingdom by Lucy Cooke (whose book Bitch delves into evolution and the female animal), and Maya Oppenheim on the line between liberation and expoloitation in sex work.
After a pitstop for prosecco and Persian flatbread, I dived back in to hear Oxford computer science professor Michael Woolridge, and Google's DeepMind AI researcher Timothy Nguyen debating whether we should worry about robots switching off our lights. The law of unintended consequences seemed a bigger risk than an evil Bond-style genius, but the panel agreed regulation was necessary.
A short but sweet solo set from Badly Drawn Boy saw him play hits like Once Around The Block and Stone on the Water from his Mercury prizewinning debut album, alongside tracks from his latest Banana Skin Shoes and a cover of Thunder Road as a tribute to Springsteen on his 74th birthday.
Fancying some comedy I ducked into to the Arena to find Guilty Feminist Deborah Frances White on a more serious tack, talking about her therapeutic use of hallucinogenic drugs to work through issues around her adoption by Jehovah's Witnesses.
If anyone can make a lengthy anecdote about their mushroom trip interesting it's Deborah, but belly laughs this was not. Fortunately Hampstead's own John Tothill rounded off the evening with his debut comedy show and there was live music from Cable Street Collective and Walt Disco to send everyone home happy.
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