It’s been over three-and-a-half years since we last spent time with confidential informant Rufus O’Callaghan and army veteran Sam Auden, so to say this third instalment of the Auden & O’Callaghan Mysteries has been long awaited is a bit of an understatement! Of course, both authors have been keeping a lot of other plates spinning in the interim, but I was excited to return to Rufus and Sam’s world as they become embroiled in a mystery surrounding some shady dealings in the military that dredges up a bunch of unhappy memories for Sam.

If you haven’t read the first two books – A Friend in the Dark and A Friend in the Fire – I’d advise doing so before jumping into this one. As in any same-couple series, the central relationship develops from book to book and the earlier novels contain important backstory for Sam and Rufus that will give readers a much better idea of who these guys are, where they’re at, and how they got there. And please note that there are spoilers for those books in this review.

Sam and Rufus first met when they teamed up – somewhat reluctantly at first – to investigate the murder of the detective for whom Rufus had acted as an informant, who happened to have been in the army with Sam. Although the pair were strongly attracted to each other and even hooked up a couple of times along the way, the book ended with them going their separate ways after a particularly nasty row. When we met them again in book two, neither of them was in a good place; Rufus lives with anxiety and depression, Sam with PTSD, and they were both struggling with their mental health and the fact that they’ve somehow blown it with the one person who seemed to truly give a damn about them. When Rufus discovers someone is trying to kill him there’s only one person he trusts enough to reach out to for help; Sam returns to New York and the two of them are soon up to their necks in it as they try to work out who wants Rufus dead and why.

Rufus went through the wringer in A Friend in the Fire because the mystery brought back a lot of unresolved trauma and unhappy memories from his childhood and about his mother, who was murdered when he was sixteen. In A Friend in the Glass, it’s Sam’s past in the military that is coming back to haunt him when, completely out of the blue, he receives a phone call from a woman offering to sell him information about Project Stonefish, a training operation that went disastrously wrong. Someone Sam cared about died as a result of what happened and Sam left the army shortly afterwards;he’s always been convinced there was some kind of cover-up but never had the means or opportunity to prove it. Until now.

Rufus can’t help being a bit sceptical. He knows Sam has never really come to terms with those events, knows that Sam’s judgement when it comes to Stonefish is compromised, and he worries that someone is manipulating him for their own ends. But Rufus isn’t going to leave Sam to go it alone – they’re a package deal and he’s going to be there for the man he loves despite not being totally convinced there’s anything to be learned from going to meet with some rando who called him at the ass-crack of dawn.

Rufus is even more sceptical when the woman doesn’t show, but Sam isn’t ready to give up. They trace her to a run-down hotel, but when they get to her room they find her dead, apparently from an overdose (although Sam thinks it’s been staged). Rufus puts in a call to his handler, Detective Erik Weaver, but he and Sam take the opportunity to have a look around before Weaver arrives and Rufus hits paydirt when he finds a phone underneath the bed. He can see several calls were made to the Javits Centre – a large conference centre that just happens to be hosting some kind of military convention.

A bit more digging, and Sam and Rufus discover there’s a lot more going on than a cover-up of a military op gone wrong, but every time they think they’ve got a new lead, it’s a dead end – more specifically, there’s a dead body at the end of it – and now there’s someone out there who wants to add Sam and Rufus to the tally.

A Friend in the Glass is clever and fast-paced, with plenty of action and lots of twists and turns that will have readers as tangled up in its threads as are its two protagonists. I loved seeing Sam and Rufus in a more secure place as regards their relationship, although there are still a few lumps and bumps along the way. Sam doesn’t like living in such a busy environment – the constant noise and the crowds can be hard for him to handle – and Rufus knows it and worries that he’s going to leave him. Thankfully, they’ve reached the stage where they’re no longer hiding things like this from each other, and by the end, are making plans for their future, which is something neither of them has really done before. I like them a lot, both individually and as a couple; they’re complicated and carrying a lot of baggage but are striving to be better because they want to be better for themselves and each other, and the way they’re so open and honest about their hopes and fears really shows how far they’ve come since we first met them. I love their working dynamic – there’s a real energy zinging between them when they’re bouncing ideas around – and given both authors excel at writing dialogue, their banter is top-notch. I continue to enjoy Rufus being a snarky little shit and Sam’s dry humour, and that these two care very deeply for each other is never in doubt. They’ve still got a way to go, but they – and we – know by now that they’re in it for the long haul; they want to make a life together – they just have to work out how to do it.

A Friend in the Glass is a quick, but satisfying read and definitely one I can recommend to fans of fast-moving, clever mysteries a featuring complex, well-drawn central couple in an expertly realised setting. I’m pleased Auden and O’Callaghan are back – and fingers crossed it won’t be too long before we get to tag along with them on their fourth and final outing in A Friend in the Wind.