Cas made sure he had a secure hold on Harry’s hand before he released the stair ward. Then he made sure Harry walked down the stairs one at a time and held on tightly to the banister with his other hand. They made slow but steady progress down to the bottom floor of the house. "Alright, you can go and play with your toys now, I’ll make you your juice and banana," he allowed, releasing Harry’s hand. He reset the stair ward on the bottom stair with a tap of his wand, just to be on the safe side.