Karev Brothers Series by Leslie North

Born into a Russian Mafia family, Vlad Karev is no stranger to violence…but this time it’s personal. Someone has murdered his father and Vlad can’t rest until he finds the killer. When the trail leads to an art gallery, Vlad wants to dig deeper, but he needs help from the owner’s daughter. The pretty redhead is far too innocent for a man like Vlad, but he’ll do what it takes to get the information he needs. His obligations are to the family, even if that means using the fiery woman... moreBorn into a Russian Mafia family, Vlad Karev is no stranger to violence…but this time it’s personal. Someone has murdered his father and Vlad can’t rest until he finds the killer. When the trail leads to an art gallery, Vlad wants to dig deeper, but he needs help from the owner’s daughter. The pretty redhead is far too innocent for a man like Vlad, but he’ll do what it takes to get the information he needs. His obligations are to the family, even if that means using the fiery woman. Madison O’Connor works hard to keep her family’s gallery going, although secretly she has little interest in art. But when she discovers her father’s been laundering money for the Russian Mafia, she’ll do everything she can to keep him out of jail. She hates to lie, but she has a plan…seduce the Russian bad boy to learn the mob’s secrets. Never mind his dangerous exterior or icy blue eyes, Madison’s going to get her family free of the mob, even if she has to use Vlad Karev to do it. As the killer gets closer, so do Vlad and Madison. But is their connection just the means to an end, or could their romance be real? less

Former Russian mobster Maxim Karev is a man with something to prove. His father’s been murdered and even his own brother thinks he’s guilty. To clear his name, Maxim has to return to the organization he left behind. He likes to work alone, but this time an FBI agent leaves him little choice—either she goes in undercover with him, or Maxim can rot in jail. One thing’s for sure—he’s not going down for a crime he didn’t commit... moreFormer Russian mobster Maxim Karev is a man with something to prove. His father’s been murdered and even his own brother thinks he’s guilty. To clear his name, Maxim has to return to the organization he left behind. He likes to work alone, but this time an FBI agent leaves him little choice—either she goes in undercover with him, or Maxim can rot in jail. One thing’s for sure—he’s not going down for a crime he didn’t commit. If playing with the beautiful agent is what it takes to prove his innocence, Maxim is prepared to go the distance. 
FBI agent Savannah Casillero never backs down. She already lost her partner on this case, and now she’s more determined than ever to find Sergey Karev’s killer. With the Mafia’s former head of security under her thumb, she finally has a way inside—as Maxim’s girlfriend. Controlling the lone wolf may be a bit of challenge, but Savannah’s confident she can handle it. The six-and-a-half-foot Mafia man is certainly not her type, but she’ll do more than play along to make it believable. 
They’re willing to work together to track down a killer, but when the ruse becomes a little too real , will Maxim and Savannah give in to temptation or hold fast to their original obligations? less

Rare bookstore owner Dmitry Karev left the Russian Mafia behind when his wife died, but there’s too much at stake to keep his back turned any longer. His father is dead and his brothers may be next. Someone’s been leaving Dmitry clues about the killer, but he never expected his informant to be a bombshell like Harper Allen. Now the curvy computer expert is testing not only Dmitry’s methodical nature, but his self-restraint as well... moreRare bookstore owner Dmitry Karev left the Russian Mafia behind when his wife died, but there’s too much at stake to keep his back turned any longer. His father is dead and his brothers may be next. Someone’s been leaving Dmitry clues about the killer, but he never expected his informant to be a bombshell like Harper Allen. Now the curvy computer expert is testing not only Dmitry’s methodical nature, but his self-restraint as well. But with his family’s lives in the balance, Harper may be the best chance Dmitry’s got to catch a killer. When hacker Harper Allen’s parents used her college money to pay off the Mafia, it was Sergey Karev who financed her education. Now that he’s been murdered, she’s repaying him the only way she can…by helping his son solve the crime. To follow the trail any further, though, she’ll have to convince Dmitry to work with her. The buttoned-up Russian seems hesitant at first, but it doesn’t take long for Harper to discover what’s beneath Dmitry’s icy cool demeanor. As Harper and Dmitry worm their way deeper into the Russian Mafia, their chemistry becomes undeniable. But with a killer at their heels, they’ll have to stay focused if they want to stay alive. less