Time to Burn

This suspense novel by Ellery Lloyd (the pen name for a British husband-and-wife writing team) posits a current day world in which time travel is possible, but only at great expense. We join a small group of travelers and their guide in 1941 London during the Blitz. En route to the return portal, one of the travelers is severely injured by flying glass from an explosion and one traveler, Sasha, does not come back with the rest of the group. This of course could be a public relations nightmare and so all resources are brought to bear to try and locate the missing person and bring her home.  Here is a summary from the book jacket:

"Mercurial tech entrepreneur Inigo Frank has perfected commercial time travel, though it is tightly regulated and so expensive that it's open only to the very wealthiest. His company, Tempus Tours, has so far been approved for just one route: a journey back to London in 1941, to the days of the Blitz, allowing the super-rich to experience the awesome sights and sounds of the aerial bombardment of the capital during World War II. It's a slick operation--routes across the wartime city are meticulously plotted, guides are extensively trained, and rules for the time tourists are strictly enforced. To immortalize his achievement, Frank enlists award-winning filmmaker Phoebe Hunt to create a fly-on-the-wall documentary. On her first day shadowing Inigo, she is set to witness the return of a billionaire property developer and his family from their trip to the past. But instead of their awe-filled return, she captures the group arriving bloodied and traumatized, with one of their number missing. Not only that, but Phoebe recognizes the missing woman, and knows not only that she's not who she claims to be but that she has every reason to harbor a grudge against her. And as events begin to unravel in the present day, it seems increasingly clear that she had sinister motives for returning to the past--and that people close to Phoebe are in danger. Phoebe must race to untangle the truth--before past and the future are rewritten."

Library Journal says in their review that "The setting is wonderfully constructed, the pacing is fast and orderly, and the characters are well-drawn. ...This is a thriller blended with old-school science fiction at its best: a story rooted in current reality and fertilized with a healthy dose of dystopia." Publishers Weekly concludes in similar fashion: "Well-wrought characters lend texture and emotional resonance to the intricate and diabolically clever plot. It’s a triumph."