Strange takes off his messenger bag before offering it to the nearest person to him: which turns out to be Zangetsu. "Drop this off in my trailer, please."

He pauses for a moment, almost held in place by some supernatural force, as he thinks things over. But it only takes a moment to think before Strange decides that nope, the good of everybody else takes precedence over him. And then, turning to Ignatius, Strange swallows his fear, offers a mental apology to Lambert and Childermass, and reaches over to take the faerie's hand. "I do. I offer myself."

He's a mercenary, after all, he's supposed to protect those in the carnival. He just didn't expect it to be this way.