They get closer to the ship. It's obviously seen better days.
They get caught (of course.)
Holly is supposed to look a lot like the captain's daughter.
Malak comes on board to steal more stuff.
They go to Malak's to take back the things he has stolen but he ends up finding them.
Malak had stolen a small cannon and some gunpower, and Jack and Will plan to give the Sleestaks who are outside a surprise. They fire the cannon (using only gunpower; no shot), the Sleestaks run off, and then take back the other stuff from the ship and leave.
They have the captain's diary and find out the ship is the Flying Dutchman. (They were planning to use the ship to leave. Didn't they consider just how old the ship was, and if they returned to the time of the ship, they themselves would be hundreds of years before their proper time?)
He's drugged Holly to make her sleep, but before she sleeps he gives her a present.
Jack rescues a still-sleeping Holly, and the captain lets them go.