Jonathan might not know exactly where he is or what is happening, but he knows that there's clearly danger and people who need help here and he will do what he can for them. Focus on the rational only, and learn more about the rest later.

He stalks the corridors with a sword in one hand and a gun in the other, the only things to come with him other than his small bag of supplies, and while he holds himself back from killing their attackers he's not above incapacitating them or sending them running. And despite his hunger he feels he's managing rather well until a door is thrown open and a purple figure emerges, along with the heady scent of fresh blood that practically cloaks him and Jonathan groans and leans against the wall to try and recover from the sudden wave of hunger that overtakes him.

The smell seems so much more obvious and easy to pick out than he's used to, and he can even tell that it isn't the other man's blood he's smelling, but it's all so overwhelming he can barely focus on anything beyond it and the thump of two hearts so close--

Two hearts. Too late, Jonathan turns to see an assassin running for him and the knife in the man's hand bites in deep, deep enough that he'd be done for if he were human, and his attacker clearly believes the same as he turns and draws a sword to attack the purple man next.