Headcrack (stylised HEADCRACK) is a website used by both Mattie and Leo in Season 1.

Mattie is seen on the website back in 1.2 and when Mia begins to push through the Anita code and Mattie sees, she uploads Anita's root code for anyone to help her with, to see what is wrong with her synth. At the same time, Max is scanning for any hint of Mia anywhere online, having been told by Leo to try. This is when Leo first gets into contact with Mattie and it's the catalyst for the beginning of the Hawkins and Elster's working together throughout the show.

Trivia Edit

  • Mattie's Headcrack forum name is: Hu-bot97.
  • Leo's Headcrack forum name is: User885.