Teen Titans Vol. 2: The Culling (The New 52)

As a part of the acclaimed DC Comics — The New 52 event, this second
volume of Teen Titans launches the mini-event, "The Culling," featuring
Superboy and Legion Lost! When the organization known as N.O.W.H.E.R.E. captures
Superboy, the Teen Titans, and Legion Lost and pits the young heroes against
each other to weed out the weak, it will take everything the most famous teen
heroes of the DC Universe have to save themselves from each other. But the
ruthless Harvest won't give up easily leading to one of the young heroes making
the ultimate sacrifice for the others.
Collects Teen Titans #8-12, #0, and DC Comics Presents
#12.