Ethereal Entanglements (Spirit Knights Book 3)

Portland has a Knight problem.

Now that the Spirit Knights' demesne has accepted sixteen-year-old Claire
into the order, she only has to convince all its Knights she belongs. Forced
into a test to prove her worth, she discovers more than anyone wants her to.

Meanwhile, Justin runs around playing janitor. He made some big messes.
Cleaning them up puts him on a new path, one he never imagined his
future could hold. All on Thanksgiving.

In this third installment of the SPIRIT KNIGHTS series, Claire thinks she
knows what must be done to save herself and the world from the plague of
ghosts the Spirit Knights leave behind.

If she’s wrong, there may be nothing left to save.