Alex was cop for the years... You always seen him as a cold man who haven't carred about anyone. What nobody know about him was that 3 years before because of his mkstake he lost the partner, what changed him, but he hif everything about it and never ever talked with this about anyone.

That was your first day of working as a cop. Since Alex haven't got a partner for a few years by the choice of the boss, you became Alex partner.