Mikey sighed, pushing a hand into his hair as he tried to pick through what information they had. The doors to the castle were thick enough to hold back most things, but even the sturdiest of wood would give way to fire eventually. "On its own? Probably a long time. Burning?" He was sure he didn't need to finish that sentence.
Looking about himself he took in the heads starting to raise from sleeping bags and the grim set to Gerard's face. "This is the worst place to be," he said worriedly. "The only way we can get them out is by going through the Entrance Hall and that would be suicidal." The possibility of the outside doors giving as they were crossing it was too strong. "Either we try evacuating by the windows to the roof or we do our best to barricade them in." Or maybe some combination of both if they could manage it.
That still left one substantial problem though. "If they break those doors down, Spence -" he bit at his lip. "That's a massive swarm of them heading up or down the stairs." And the common room doors, the library doors, the hospital wing doors, who knew if they were strong enough to hold against that many at once. "We can't sit in here waiting to see whether they get through." Or he had no plans to, anyway.
He glanced round at Gerard and Jon, evaluating. They were all tired, all low on sleep, but the four of them firing out spells together would make a sizeable dent in any horde. "It's our damn castle, right?"