He wishes someone else were in his place. Someone better.

As it is, he scarcely knows how to offer comfort. It isn't too much to ask - it shouldn't be. He isn't even sure if it is in this scenario, or what is truly going on beyond Eponine's flawed perception. He's already decided that he'll find out. It's the least he can do.

"...If naught else can be done, where you are now..." If talking to Nadine doesn't help, if no other can stand in her place. "I will come for you, Eponine. As soon as I am cleansed of this wretched brand."

Part of him wants to reach over, to offer her physical comfort, but he can't bring himself to. He can't imagine how someone like him would.