On the same day that Simon can become a millionaire if he manages to sell his LISA algorithm, he writes to Irina via a Russian dating app: ‘Are you coming to Bilbao?'

If Simon doesn't fix LISA in three months, it will be Sanders'. Meanwhile, Irina is looking for her family's killer. All she knows is that they call him The Spider.

Irina asks Simon to marry her so she can work in Spain. What she hasn't told him is where: Boris's restaurant, La Araña, her sister's murderer.