Barty laughs his ass off when Harry tells him. It’s a warmer laugh now, more like a brother than a crazed man in the skin of his enemy. He helps Harry study a few useful spells, fire resistance, levitation etc. Then he helps Harry write to Sirius and Bella, as well as promise to do some snooping for the other tasks. Harry almost doesn’t want to leave. He has a sinking feeling that these moments with Barty- Sane, Warm, brotherly Barty- might be few and far between the more time passes.