Where do you get the bucket on vampire's curse island?
The bucket is in the armory attic next to a large plant. You
need it to water the little plant higher up near the boarded
window.
Take the water bucket to the geyser outside (you can break the
door open on the right side of the library using the crowbar). Back
in the armory, climb the plant and use the crossbow. Shoot some
arrows into the wall at the left, then climb up on them to the top.
Use the crowbar on the window boards, then water the little plant.
It is apparently a beanstalk.