Couple of Trench field agent days thoughts.
By the time Darling started, he'd already been an agent with the Bureau for several years and was a senior field agent. His service record was quite impressive; Trench had both led and been a part of a number of missions to investigate Altered Items.
Until Darling came around, the person Trench considered himself closest to was Marshall. She was a great agent in her own right and Trench had a lot of appreciation for how she worked and her overall personality. They worked a lot of missions together. She wouldn't beat around the bush with him and he loved that. She saw right through his bullshit and called him out on it constantly. They clicked. While he wasn't quite as close to Tommasi and Salvador the way he was with Marshall, they still had an excellent working relationship and Trench trusted them, enough to make them all his Department Heads upon his promotion.
Save for Northmoor, Trench wasn't really hated by anyone. He was liked well-enough, he was certainly competent at his job and very well-respected in his position, and he had a reputation of someone who would put everything on the line for somebody else but wasn't someone you could really get close to. The people assigned to his command knew that he'd be looking out for them, that he'd be willing to throw himself into the fray for any one of them without hesitation.
A large part of this distance between him and others had more to do with his relationship with Northmoor than his personality. Getting too close to someone the Director couldn't stand might paint a target on your back and Northmoor wasn't a man you wanted to be on the wrong side of.
It was no secret the two of them did not get on. Northmoor would openly attack Trench in front of others whenever he, by his standards, stepped out of line, they would constantly be at odds, Northmoor would make his life hell some days. It escalated to physical altercations a few times. Trench had his own ideas about how missions should be run and how he'd interpret the rules and Northmoor hated that. Hated him for it. He was insubordinate. Trench couldn't be fired because not only was he a good agent, but it would be some kind of admittance on Northmoor's part that he really couldn't control Trench and for a man obsessed with control and power, that wouldn't stand. And, reluctantly, there was some respect there on Northmoor's part for the work the man could do. (Truthfully I don't think he would've relinquished his position as Director had it not been Trench spearheading the effort, especially knowing what awaited him. With the amount of power that man possessed and his personality type, forcing him if he was entirely unwilling would've been next to impossible.)
While some found Darling to be eccentric and rather annoying, Trench actually quite liked his personality. Darling could talk, oh how he could talk!, and that was just fine with him because he was far more content to listen and respond rather than be the one doing all the talking. Darling at first thought he was just pitying the new researcher, but Trench was genuinely interested hearing him talk about his work and seeing the way he would lose himself in his passion. Darling lived in a whole different world than he did and it was fascinating.
The cracks in Trench's marriage to Kate had started forming a while back—it was difficult to be married to someone who was also married to their work and worked a job that they knew was dangerous but legally weren't allowed to know the full extent of. The more he'd seen, the more distant he'd become some days, the more he'd take home and only be able to discuss in broad strokes. Eventually it was easier to stop saying anything about it at all. Kate had wrangled some information about Northmoor out of him, especially after one night where he'd come home looking more haggard and run down than usual, and while she didn't know anything about his parautilitarian abilities, she knew the man. Met the man at FBC functions. Understood that he was on some kind of power trip and that her husband was suffering for it.
The stress of that didn't help his marriage any. He was also trying to organise an entire coup, so to speak, right under Northmoor's nose. Trench hoped it didn't come to an actual fight and that the man would listen to reason, fantastical as that sounded, but in order for it to work, everything had to be put in place. The effects of Northmoor's growing megalomania and the exponential increase of his powers leading to loss of stability/control were being felt throughout the FBC and Trench's personality being what it was wouldn't allow him to not do something about it. He'd bring all of them down with him. Trench was already used to going against the man, doing what he thought was best. What was one more time?
This was something that he was working on for months. He had to. Marshall and Salvador were involved; he'd need a team—competent backup in case it escalated. With power like his, raw, pure energy, containment was the only viable option. They'd need something that could withstand the heat and power Northmoor could output. They needed to redirect all that energy somewhere. Research was involved; plans for the NSC were drafted and construction had to happen. That was well out of Trench's wheelhouse; he wasn't a scientist, he was a field agent. Let them deal with the logistics.
The confrontation was as explosive as Trench imagined it would be, but what was most surprising was that Northmoor was able to see reason in the end. He listened, even reluctantly agreed with Trench's points. He was a danger to himself and everyone else around him, threatening the Bureau which went against everything a Director was supposed to stand for. When met by the totality of Trench's resolve and the culmination of all the work that had been happening behind the scenes, Northmoor had little choice but to accept.