The Ninth Saddle: A Dragon-Bond Romantasy by Elven King

Sable Quint forged her enlistment papers for one reason: to learn who killed her brother. She never planned on the dragon. Korrath has grounded himself for a year, refusing every rider, grieving the man who died in his saddle. Now, impossibly, the old war-dragon chooses her. And a dragon's bond comes in pairs: one dragon, two riders, two minds laid bare with nowhere to hide. Her co-rider is Wing-Captain Veyr Castellan. The army calls him the Widowmaker. Sable calls him the man who watched her brother die. The link between them has no walls. He will feel her hatred cool, and her fear sharpen. And when she lies about why she is really here, he will feel that too, ringing through the bond like cracking iron. To find the truth about one death, she must deceive the only man who can feel every lie she tells. No way out but through.