Imzadi is a non-canon Star Trek novel by Peter David, primarily exploring William Riker's assignment to Betazed and his early relationship with Deanna Troi. Imzadi has a complex structure, involving time travel through the Guardian of Forever, but a straightforward plot of love and rescue. Troi's history with Riker had been introduced in the pilot episode of Star Trek: The Next Generation, "Encounter at Farpoint"; this also included the word imzadi, a Betazoid term of endearment usually translated as "beloved". The novel expands on the meaning of imzadi when Troi explains that its literal meaning is "the first," not necessarily referring to the first sexual partner but, as Troi puts it to Riker, "the first to ever touch your soul." Source: Wikipedia (en)