These hints got us a few, but there are still a few left to find.
Excluding the things we've already found on the way to town, it needs:
1 - Something that attracts crows 2 - Yoruga 3 - A glass bulb to hold the ingredients
Way back in Chapter 1, you may remember that we used dove eggs to lure the crows in the castle.
There may still be some eggs laying around the house.
Geron had the misfortune of sharing a bedroom with the bird-cages; check the ground floor.
One dove egg can be found in the birdcage above Geron's bed - you'll need to search the droppings to find it.
A type of herb - Gwinnling had a book of herbs that may prove useful while we search.
Cast your mind back to chapter 1 - Hilda' stall had many things on offer.
Maybe she was selling herbs?
That would throw a wrench into things, but we have a track record with tarps and curtains.
It would be a shame to end the streak.
Use your knife on the Hilda's stall, then move the bowl aside.
You can identify the root by using Gwinnling's book of herbs on it.
All that's left is to get a glass bulb and place all of the ingredients inside.
Once again, Gwinnling was far more prepared than Geron - he probably kept one in his attic.
Check it out.
It may be a bit difficult to see, but there's a pile of glass shards on the far left.
You could probably shape them into a glass bulb with a bit of magic.
Place the repaired glass bulb on the nearby tripod, and put all of the ingredients inside.
1 - Mandrake 2 - Yoruga 3 - Thrashbeard (Lichen) 4 - Dove's Egg 5 - Icicle
When they're all inside of the glass, all that's needed is heat.
Use your flintstone and tinder on the oil lamp beneath the bulb.
Perfect - all we need now is a good bait.