Uncanny X-Men #155

The X-Men soon learn that Princess Lilandra has been kidnapped, and if she is not found within 24 hours, the Shi'ar Armada will destroy planet Earth. After recruiting the newest member of the Avengers, Tigra, the X-Men track down the true culprits behind the abduction. Now the Children of the Atom must face the deadliest warrior in the Shi'ar Empire - Deathbird - and her even deadlier conspirators - the sinister Brood! And in this battle, one shall fall!