Ishmael uses the hat to take the form of one of the little girls he saw earlier in the building. He also tries to recall the name of any of the teachers or any of their handlers that took them outside so he can use it.

He then goes further inside now that he has a backup in case he gets seen somehow. He especially tries to be in covered areas so that his skills can be useful but also so that if he is seen as a little girl he has a plausible reason about why they missed him.