'The Undivided are divided.
'The psychic twins Rónán and Darragh have been separated by a traitor Druid, Amergin, who has thrown Rónán through a rift into another reality. Now time is running out for Darragh. If Rónán isn′t found soon, they will both die.
'Meanwhile, Ren Kavanagh has no notion of where he comes from and is plagued by mysterious injuries. Then he meets the enticing and mysterious Trása, and before he can figure out how it happened, he is in serious trouble ...
'Ren′s life is about to become more bizarre and dangerous than he could ever have imagined.' (From the publisher's website.)
'Ren of the Undivided and his half-Faerie companion Trása must find a way to stop the Matrachai, who want to eliminate every magical race in existence. Only the Undivided hold the key to stopping them, and even the Faerie Brethren have turned to Ren for assistance. With the help of the Pete and Logan Doherty, the human twins stranded with them, Ren must find a way to save them all, especially his twin brother Darragh. Reunion is the third book in the fabulous Rift Runners epic fantasy series, following on from The Undivided and The Dark Divide, and switches through time portals between the contemporary world and a Celtic Druidic Britain.' (Publisher's blurb)