Since the love/cousin/polygon of Opal/Samson/Ursula/Max/Sully demands it, Max came into this compartment late as usual, nearly missing the train, hauling his trunk, his owl cage fastened to it and banging along behind, much to the dismay of his owl, Babayaga who screeched like her namesake. His broom was tucked carefully beneath his arm in its special travel case as he didn't trust it to his trunk, and he took the time to stow that first before shoving his owl's cage under his seat and his trunk up on the rack just as the train began to move. All the time he was grumbling, as usual, about having to come to London just to go back to Scotland, but once that was over he took over the compartment, giving Ursula a kiss on the cheek, rumpling Opal's hair if he was there just to annoy her, giving Samson a .. do Wizard's do high fives? And settling next to Sully on "their" bench. Assuming Sully is chill with that as usually their limbs will get all entangled during Max's requisite post Trolley nap later in the day. (He also had some of Eden's chocolate cakes left and passed those around during Trolley time too - they were slightly squished inside his robes).
Then he said "Did you hear about Snape being made Headmaster? S'brilliant." And settled back in his seat.