Spoilers for Crowven's route!!
First, you have to check out what Vasshole and Crowven are up to. Then, you have to stick around and see what the Headmistress has in store for the two of you. Afaik, there isn't actually a single instance in HFSH where running away works out well. Once you're in the office, figuring out the right choice is a little tricky, but you have to "admit" that it was all your idea, before telling Aesirel that Crowven had nothing to do with it. Obviously, Aesirel isn't buying it, but this buys you more time, leading to the single best interaction in HFSH. After Theo's stunningly cunning disguise saves the day, you have to tell Aesirel that you just wanted Crowven to like you. This seems to have the effect of convincing the universe to take pity on you, as it should be smooth sailing from there, with the player now being locked into succeeding at the route. Have fun! I hope this helped!