Reece and Lara are jumping through time trying to escape Reece's partner, Carl, with the aide of an ancient medallion which they have half of. As they jump through time every three days, they help a couple work through whatever issue is keeping them apart. In this installment of the series, Reece and Lara spend quite a bit of the book in a Mediterranean harem where a Governor's wife is in jeopardy because of a jealous first wife. After Lara and Reece are able to convince the Governor of his wife's treachery, they jump to ancient Japan to a Samurai camp where they must help a samurai and the woman determined to kill him work out their differences.
If you're a person who doesn't mind f/f/m/m sex in your books, than you'll have no issues with Reece and Lara's jump into the Mediterranean harem they find themselves in at the beginning of Twice Upon a Time. While the relationship between the Governor, his wife and their servants was crucial to what was happening in that particular storyline, it was the relationship between Reece and Laura that had your focus as it was tested because of what was happening with the individuals in whose bodies they are currently inhabiting. Jealousy and trust were facets to their relationship that were tested and which ate at Reece.
But it's when they jump to Japan that I feel they were really tested. Hana, the woman who wants to kill the samurai as an act of revenge for her brother's death, has trust issues. Trust in the samurai who intrigues her, even when she wants to kill him. Trust in the other men in the camp. And trust in herself to stick with her plan. It's that lack of trust and Lara's comments about how she could never be in a relationship with a man she doesn't trust that causes turmoil for Reece. He's been lying about what really happened to Laura and realizes their entire "new" relationship is built off that lie.
I loved the prologue as it gave us a little more insight into what happened that caused Laura to die. I would have liked more information into why Reece did what he did and what is so awful in his past that he's afraid to reveal it. I'm hoping we get more of that as we leap into the next book, which appears to take place on a pirate ship (fun!!).