Which means everyone will only go there once. However on Darkest and Stygian/Bloodmoon they will refuse to go back to the Darkest Dungeon, you can return them there on Radiant, but it will come at the very heavy cost of them starting with 80 stress and a 1% virtue chance.

Heroes who complete a DD quest will no longer count to your roster limit and if you sent them on other missions they'll give everyone (except other DD survivors) 50% more resolve exp.

Reinforcements are always on even if you turned them off.

You cannot escape so easily from this place, if you must you will lose one random hero unless you only have one hero left, so unequip all of your trinkets before escaping if you have to.

There are no obstacles, traps or curios that require keys so don't spend your money on them.

Before explaining the missions themselves I'll explain a few mechanics unique to the Darkest Dungeon: This place is unlike any other region in the entire game, every DoT does a lot of damage, every stress inducing attack causes a lot of stress, attacks hit hard, and every battle has a good chance to be your last there.

Darkest dungeon mission 2 map layout