The extincts. 1, Quest for the unicorn horn
(Book)

Volume numbering from spine.

Meet Scratch, Martie, Lug, and Quito, members of a secret organization called R.O.A.R., or the Rescue Ops Acquisition Rangers. When their boss, Dr. Z, finally calls on them for their first big mission, the team heads to Siberia to retrieve an ancient unicorn horn from the thawing permafrost. Scratch is thrilled at the chance to prove his worth to Dr. Z--but as soon as they land, the team runs into a mysterious enemy determined to take them down.