Jordan (Pendragon Legacy #3)

A DANGEROUS MISSION
Vivianne Blackstone devotes herself to her career, putting her love life on hold. Her latest project is a spaceship designed to protect Earth from the deadly Tribes. But its engineer, the alluring Jordan McArthur, now threatens both her job and her wary heart . . .
AN UNDENIABLE DESIRE
Jordan's past goes back to King Arthur, and he must find the ancient artifact that can save the galaxy. Vivianne's ship is his best hope, but convincing the fiercely independent beauty won't be easy. Especially when the passion flaring between them burns through their defenses - and love is the last thing they need to survive.
Rated '4/5 - Explicit open door' for steam/spice/heat level.