After the TARDIS squeezes his hand, the boat settles back to normal quickly. He's reminded that she doesn't enjoy the motion, so things should stay fairly level and gentle from now on, even if Johnny decides to move around again.

He feels the TARDIS looking a little closer at his feelings, and does nothing to hide from her. At the moment, the most she'll find lies in his concern for Johnny and his frustration at him getting hurt again while he wasn't around to help.

He rubs at Johnny's back, hoping to comfort him while he wonders who this other person is, if not Zagreus. It seems like Johnny can't catch a break. "You're safe here."