Highsong Series by Laura Jennings

Sia is a Risen, a genetically engineered, sapient, and psychic dolphin on board a science-ship sent to check the stability of a terraformed planet, Ptaal, that lost contact with the Ninth Democracy 300 years before. Also on board is her human friend, Harp, the result of an illegal experiment that attempted to make a psychic human. Both of them look forward to their first mission, because none of the alien Viciss show signs of targeting Ptaal. Sia and Harp are wrong... moreSia is a Risen, a genetically engineered, sapient, and psychic dolphin on board a science-ship sent to check the stability of a terraformed planet, Ptaal, that lost contact with the Ninth Democracy 300 years before. Also on board is her human friend, Harp, the result of an illegal experiment that attempted to make a psychic human. Both of them look forward to their first mission, because none of the alien Viciss show signs of targeting Ptaal. Sia and Harp are wrong. Because the Viciss aren’t coming. They’ve already arrived. less

Nearly two years after surviving the incident on Ptaal, the unique psychic abilities of Harp Hess and his dolphin companion Sia have captured the attention of the Ninth Democracy. Isolated from his mother and trained at a secret facility to battle the alien threat of the Viciss, Harp is reluctantly on route to his first real battle. But an ambush leaves Harp and Sia stranded, in the company of a ragtag militia desperate to save a doomed planet... moreNearly two years after surviving the incident on Ptaal, the unique psychic abilities of Harp Hess and his dolphin companion Sia have captured the attention of the Ninth Democracy. Isolated from his mother and trained at a secret facility to battle the alien threat of the Viciss, Harp is reluctantly on route to his first real battle. But an ambush leaves Harp and Sia stranded, in the company of a ragtag militia desperate to save a doomed planet. As Harp struggles to form an uneasy alliance, Sia realizes this time, their greatest enemy may come from within ... less