There is one truth we can't escape: that somewhere in our past a witch is trying to rewrite everything we ever knew - and all we can do is wait - wait for the moment she either succeeds or fails."
-- Hermione Granger (CC4.1)
Hermione, Harry Potter, Draco Malfoy, Ginny Weasley and Ron Weasley stand together to take responsibility. However, there is nothing any of them can do until they know where Delphi is and what she is doing (CC4.1).
Likely to take place shortly after the previous event or possibly the next day
This event takes place during the Voldemort Final timeline, as described in the essay "Albus Potter and the lesson in Quantum Mechanics" by Nick Moline.
The stage directions describe it as "almost a Spartacus moment" when Draco Malfoy says:
"Then it's a negligence I too should face…. Hermione and Harry have done nothing wrong but try and protect us all. If they're guilty, then I am too." (CC4.1)
In spite of them standing together in quite a humorous way, there is still real fear when it is realised that none of the people there are likely to be alive if Delphi achieves her goal (CC4.1).
From the Web
Pottermore: Harry Potter and the Cursed Child
The theatre production opened in the West End of London at the Palace Theatre on 31 July 2016, with Noma Dumezweni in the role of Hermione Granger, Jamie Parker as Harry Potter, Poppy Miller as Ginny Weasley, Alex Price as Draco Malfoy, Sandy McDade as Minerva McGonagall and Paul Thornley as Ron Weasley: Harry Potter and the Cursed Child, Parts One and Two