Multi page layer import

Hi,

Doc 1 has 10 pages

Doc 2 has 10 pages

How do I imnport Doc 2 in to Doc 1 as a new layer where page 1 overlays page 1, page 2 overlays page 2 etc. So far I can only see a way to do this via the layers panel manually page by page, there must be a way to map the pages so I can do all 10 in one go?

Any ideas?