last, but the British mystery series starring David Tennant continues. Another murder could be solved -- and the trial based on the events of season 1 resolved -- by the end of this finale. 6. Academy of Country Music Awards, 8 p.m. ET Sunday, CBS Luke Bryan and Blake Shelton return to host the 50th annual awards. Christina Aguilera is set to perform a surprise duet -LRB- yes, that Christina Aguilera -RRB-.