Double target player's life total. Shuffle Beacon of Immortality into its owner's library.
2/1/2007 If you double a negative life total, you do the real math. A life total of -10 becomes -20.
7/15/2007 Beacon of Immortality’s effect counts as life gain (or life loss, if the life total was negative) for effects that trigger on or replace life gain (or life loss).
7/15/2007 If a Beacon is countered or doesn’t resolve, it’s put into its owner’s graveyard, not shuffled into the library.