When Hook kills a unit with Altar of Memories on board, can you use Altar of Memories before looking at the top 5 cards from Hook?

Ruling: No, Altar of Memories triggers after all of Hook's instructions are completed. You cannot use Altar of Memories before looking at the top 5 cards.

Sequence:

• Hook begins resolving and kills the unit
• Altar of Memories trigger is added to the chain as pending
• Hook completes all its instructions (look at top 5, possibly play one, recycle the rest)
• During the next cleanup, Altar of Memories trigger finalizes and goes on the chain

Nuances:

• All triggered abilities are added to the chain as pending when an inciting event happens, regardless of whether the inciting event is a spell or activated ability
• Triggered abilities finalize during the next cleanup after the inciting event completes