"I don't think Voldemort is capable of having a kind son - and you're kind, Scorpius.... Voldemort couldn't have a child like you."
-- Albus Potter (CC2.16)
As they make up, the Headmistress, Minerva McGonagall comes into the Library with the Marauder’s Map, having seen on it that the two were there together. However, Albus and Scorpius hide under the Invisibility Cloak, which Albus has stolen from his brother James.
Professor McGonagall wisely decides that the Map must not be working correctly as she cannot see them. Once safe, Albus tells Scorpius that they need to use their experience of being “losers” to change time again with the Time-Turner and this time prevent Cedric Diggory from winning the Second Task of the Triwizard Tournament (CC2.16).
Later the same day, just after the previous event, September 2020
This event takes place during the Roseless timeline, as described in the essay "Albus Potter and the lesson in Quantum Mechanics" by Nick Moline.
During their argument, Scorpius reveals that he had hoped that the changes to time might have resulted in his mother Astoria still being alive, but instead:
"I’m still the child of Voldemort, without a mother, giving sympathy to the boy who doesn’t ever give anything back." (CC2.16)
He makes Albus finally understand that his problems with his father Harry aren't so bad (CC2.16).
From the Web
The theatre production opened in the West End of London at the Palace Theatre on 30 July 2016, with Sam Clemmett in the role of Albus Potter, Anthony Boyle as Scorpius Malfoy and Sandy McDade as Minerva McGonagall: Harry Potter and the Cursed Child, Parts One and Two