A.C.E dropped a group concept photo for 'Under Cover.'

The boy group is coming back with the 2nd mini album. The 5 members - Jun, Donghun, Wow, Kim Byeong Kwan, and Chan- came together for a strong, fierce cut. The teaser also came with the description, "Because I want you to be mine, Be mine."

'Under Cover' is set to release on May 17.