Sinclair follows Jack accordingly, still a few paces slower thanks to the aggravatingly human rate at which his leg is healing.

They both keep quiet as they walk, listening. Jack's hunting a Big Daddy, but Sinclair is equally as concerned about the splicers that tend to flock to Little Sisters the way Jack is right now. He trusts that Jack is certainly more prepared to take on a Big Daddy than your average splicer would be, but he doesn't trust that Jack can take on a Big Daddy and the splicers that think they're prepared.

Maybe he should have tested his own gun before they took off.