Moves quickly to capture shelter with magic (4,4)

'magic' is the definition.
(I know that Dark Arts is a type of magic in Harry Potter)

'moves quickly to capture shelter' is the wordplay.
I cannot really see how this works, but
'shelter' could be 'ark' (I have seen 'Ancient shelter' mean 'ark' so perhaps 'shelter' could also mean 'ark') and 'ark' is present in the answer.
'moves quickly' could be 'darts' (I've seen this before) and 'darts' is found within the remaining letters.
No letters remain.
This may be the basis of the clue (or it may be nonsense).

'with' acts as a link.

Can you help me to learn more?