Unsolved Mysteries has returned. And not a moment too soon. The pioneering true-crime series originally began as a series of specials back in 1987, hosted by such imposing figures as Raymond Burr, Karl Malden, and Robert Stack. And when it became a full-fledged series a year later, Stack returned as the host and erstwhile narrator, able to inject even more weight and just the right amount of self-awareness, into tales of kidnappings, lost loves, UFO sightings and missing persons (amongst other things). The Stack-led Unsolved Mysteries (with a period where Virginia Madsen was installed as a …