Jake, Caesar, and Izmel are CIA agents working undercover. They have a boss named Rolfe (lady with the glasses). Jake and Izmel have infiltrated a gang called "the Mercifuls", and Caesar is working undercover at the garage (which she loves doing). Their goal is to take down powerful drug cartels, but there are also corrupt government officials involved, and they are working to identify which ones so they can take them down too.
With Rolfe's blessing, Jake is the one who calls the shots in their operation. His method is to set different gangs against each other so they take each other out, but no one will know the CIA is involved at all (the CIA does this in real life). When this story begins, Jake is already in the middle this mission. He helped the Mercifuls take down a Mexican cartel and was in the progress of helping them take down a Russian gang when Shin sabotaged his car with his scam, which caused Jake to be late to the Mercifuls' battle with them. And Jake is known to NEVER be late for anything. He's also known as a neat-freak, which comes into play later.
The CIA knows that the owner of the Royal Roader casino (Ross Trautvein) is a big drug dealer, so the CIA used the Mercifuls to arrange a major deal, and then secretly ruined the deal to make Ross look unreliable. Jake was hoping that by sparing the lives of the gang called "Mass" (who were the middlemen in the deal), they would testify against Ross AND the Mercifuls, but Shin's foster-brother, Gren, screwed that up by killing off his own gang members. Mass being able to testify without someone corrupt interfering had been a long-shot anyway, but Jake thought it was worth a try. Eventually, they'll build a solid case against Ross to put in him jail, but they also know that Ross is the key to identifying corrupt high-level officials and politicians, so they're working on that now.
It's believed that Jake has tendency to spare lives so he can use that later as an owed favor, or to manipulate them in case he needs a backup plan-- like pawns on chessboard, which Izmel was just musing about. He did this with Mass, and again with Gren. Apparently he did this by sparing the life of the son of the motorcycle gang leader's brother. Like a champion chess player, Jake always thinks two moves ahead.
However, there's small hints that he may have spared lives because he's not quite the cold-blooded killer he wants everyone to believe he is. Three times now, he could've killed Gren, but did not. Gren is a risky loose cannon for both Jake and Shin. It had been the plan to kill off all of Mass, but it looks like he changed his mind after seeing Gren in the back of the van. And Izmel had a suspicion that Jake spared the motorcycle gang member's son because he was a little kid.
This motorcycle gang has already been attacked by the Mercifuls in the past, so they have no love for them. The son who's life was spared now comes into play as leverage with the gang. He's going to use the motorcycle gang to take another hit on Ross.
Izmel is aware of EVERYTHING Jake does and thinks his reckless actions are going to get him killed soon. He knows about Jake's serious involvement with Shin, which has caused Jake to make small mistakes, or dangerously alter his plans: specifically, when Jake revealed his face to Ross (dressed as a cop) when he wasn't supposed to be seen. He's been late to meetings a couple of times, and on one occasion appeared in soiled clothes. Benille- a high ranking Mercifuls member and someone who is just as dangerous as Jake- is getting suspicious of Jake because he's been acting out of character, especially when Jake told him he let Gren go (smart move on his part to admit this, because Jake knows Gren will be probably stupid enough to show up yet again). Ross has always been suspicious of Jake, and it's only his fear of the Mercifuls that keeps him from doing anything right now. The motorcycle gang leader wants Jake dead, but won't act just yet. Jake is counting on using and killing him before gang leader tries to kill him. But it does sound like they want to get revenge on the Mercifuls, which could work to Jake's advantage.