Ultimate Spider-Man v17 - Clone Saga (2007)

Collects Ultimate Spider-Man (2000-2009) #97-105.
As Peter Parker tries to sort out his relationship with the X-Men's Kitty Pryde and Mary Jane, he's interrupted by the debut of the Ultimate Scorpion! But a conspiracy is uncovered as his identity is revealed to be a clone of Peter Parker! And that's just the beginning for Spider-Man.