It seems unlikely that a sightless private detective could be of much use, but in “Blind Vigil,” the seventh book in Matt Coyle´s series featuring San Diego gumshoe Rick Cahill, the protagonist is determined to prove the doubters wrong. Blinded by a gunshot in “Lost Tomorrows” (2019), Rick´s nine-month-long recuperation is interrupted when his on-again, off-again partner, Moria MacFarlane, asks for his help. Rick´s pal Turk Muldoon thinks his girlfriend, Shay, might be cheating and want´s her followed, but Moria is reluctant to take the case. The last time she exposed a cheating woman, the jealous husband killed her. Would Turk be capable of something like that? Moria needs Rick´s help in assessing his state of mind. After talking things over with Turk, Rick assures Moria that his friend would never hurt Shay, so Moria accepts the assignment. And just like that, Shay is strangled to death in her bed, Turk is arrested, and the evidence against him looks solid. Moria, consumed with guilt and furious at both Turk and Rick, is convinced that Turk is guilty. Rick isn´t and, white cane in hand, ventures into the world to hunt down the real killer.