The Devil's Eye — Jack McDevitt

Alex Benedict, interstellar antiquities dealer, and his assistant, Chase Kolpath, are on vacation when they receive a cryptic message from Celebrated writer Vicki Greene, whom neither has ever met, asking for help. But when they return home, Alex discovers that Greene has asked for and been given a mind wipe. She has no memory of her past life or of her plea for assistance. Yet she has transferred an enormous sum of money to Alex. But for what purpose?

To answer that question, Alex and Chase venture to the place where Greene had been vacationing prior to sending her message. It is the most remote of human worlds, literally outside the galaxy. There, they will uncover a secret connected to a decades-old political upheaval, a secret somebody is desperate to keep hidden -- though the price of that silence is unimaginable...