# Using shape keys with vertex hooks

I basically set up a plane with a Subdivision Surface modifier and a ShrinkWrap modifier. I added hooks to all 4 vertices of the plane. I added another Empty in the middle that was the parent to the hooks.

I then added two shape keys. I modified the second to move two vertices down when the value was 1. It works well in Edit Mode, but escaping Edit Mode and moving the Shape Key's value slider moves the vertices only slightly:

I tried removing the Shrinkwrap modifier, but it yields the same error. Only once I removed all the Hook modifiers did the shape key work in Object mode. Is there a way to use hooks and shape keys at the same time?