Finally, a spotlight on Ressler explained why he came back in such bad shape.
While Liz's death hit everyone hard, The Blacklist Season 9 Episode 7 argues that it affected Ressler the worst among the Task Force members.
Red was likely affected the most, but there's the whole season to explore that storyline.
But Donald made the most of his time in this spotlight episode.
It was a shame that just when Ressler and Liz appeared to be coming together, her unexpected death on The Blacklist Season 8 Episode 22 ended that possibility.
Granted, Ressler's infatuation with Liz did seem to come out of nowhere, and it appeared like she was using him for her purposes. She didn't seem that into him.
But throughout last season, Donald emoted more than we had ever seen before when it came to Liz. Maybe he kept his feelings stuffed down inside of himself this whole time, but he was so stoic that it didn't show through.
Whatever, he showed how he felt in this episode as it was trying to track down Red, who Ressler blamed for Liz's death, that sent him on the spiral he was on for the next two years.
So the injuries sustained when he crashed while pursuing Dembe and Red were what precipitated his two years of an oxy-induced walkabout.
So it was the doctor's fault for prescribing oxy to an admitted addict. Well, Ressler needed some painkillers after his accident. If doctors had an effective, less addictive option, there wouldn't be a country full of oxy addicts, would there?
Donald interpreted Harold's opinion that Liz would want them to look ahead to mean that he should leave behind everything that reminded him of Liz, including the Task Force and Red.
He was in absolutely the wrong frame of mind to have a bottle of oxy put in his hand, as his sorrow and pain combined to rekindle his former addiction.
Ressler had to reach rock bottom before starting his climb again and getting his drug-addled self rolled by a dealer, and his associates certainly qualified as that.
Snapping at a well-meaning boy who was attempting to help him didn't help matters, either. But that was when things started to turn around for him.
Lauren came after him for how he had treated Theodore and wondered who this man she had welcomed into her motel.
But she made an excellent decision to send Ressler to local mechanic Willy, looking for menial help. When Willy discovered that Donald knew cars, he hired him to help restore his classic Nova.
That was the first step to help Ressler remember who he was. Working on the Nova brought back memories of repairing cars with his father.
Then Donald got to play the hero once again, after learning that Lauren's cop husband Shane had been abusive both to her and Theodore.
He felt a debt to Lauren, who had shown kindness to the troubled man when she had no reason to. Also, he had developed an affinity for Theodore, who had shown him how to have hope again.
First, he resurrected the Nova, and he felt joy for the first time in a long while driving it down the road with Willy.
That convinced him to attend the birthday party for lonely Theodore, which Shane crashed. Despite Ressler's attempt to throw him off their scent earlier, Shane had tracked them down.
Donald arrived just in time, tackling Shane as he was about to give Lauren a beatdown.
Ressler's shooting of Shane was justified as self-defense, as Shane had made it known what he planned to do to Lauren when he tracked her down.
Once she found out that Donald was a decorated FBI agent, she attempted to talk him into going back, which he eventually did when Harold called on The Blacklist Season 9 Episode 1.
The whole Liberty Falls experience helped Ressler start to heal, a process that continued in the present.
When Cooper first mentioned that Agnes was planning a celebration of Liz's life on the anniversary of her death, Ressler begged off, asking for time off instead.
Donald made the most of his day off, starting with a stop at the barber to lose the beard and get his shaggy hair trimmed, with what remains to remind him of the man he was before Liz's death.
Then came the trip to the florist, where he picked up Liz's favorite flower, purple carnations. That's when it first became evident that he meant to visit Liz.
Finally, he visited her grave, a significant step if he was to get past her untimely passing.
That scene wasn't nearly as sad as it could have been.
Instead, Ressler caught Liz up on what he and all her other loved ones had been doing over the past couple of years.
He also referred to Tom, next to whom she was buried, admitting that he had always been jealous of Tom.
Now Donald faces one more big hurdle, leaving the oxy behind while keeping it a secret from everyone except Park, who already knows.
To review Ressler's career, watch The Blacklist online.
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Dale McGarrigle is a staff writer for TV Fanatic. Follow him on Twitter.