With only a few episodes left, NBC’s Grimm season six continues to be one of the show’s finest seasons. Episode nine titled ‘Tree People’ is another outstanding addition to the series, with the focus on an eco-warrior Wesen and a blood-sucking tree. The episode kicks off with Team Grimm examining the mirror in Nick’s bathroom. Adalind (Claire Coffee) believes there’s a possibility whatever is in it is attached to Eve. Rosalee (Bree Turner) reminds the group Nick also saw the skeleton head creature in the mirror, and Nick (David Giuntoli) confesses he also saw it in a dream. Diana (Hannah R. Loyd) overhears and interrupts, telling Nick it wasn’t a dream – it was a premonition. Diana says it will happen in the other place that exists “through the hole in the mirror,” freaking out the adults in the room who pledge to never look into a mirror without someone else in the room.
Elsewhere, two hunters drive through the woods, come upon a deer, and the passenger shoots at it from their car. The passenger thinks he hit the deer and both men give chase. The shooter makes it to the downed deer first and before he can slice it open, he hears something moving through the woods. Tree roots tangle around his feet and he’s pulled deeper into the forest. His friend finally catches up and watches as his hunting partner is killed by a tree monster. The driver races back to his car minus his now-dead deer-killing passenger. Glancing back, the driver slams into a tree.
Nick’s ready to shave so he grabs Adalind, following the new “don’t look in the mirror alone” rule. Nick tells Adalind he thinks the mirror demon knows he’s a Grimm, but he’s worried about her since both she and Eve are Hexenbiests. Adalind promises not to look in any mirrors without him, and after Adalind wonders aloud if the thing isn’t scared of Grimms, they both decide he looks good with the stubble and quickly cover up the mirror again.
Wu (Reggie Lee) is out at the crime scene and the driver somehow survived the accident but won’t leave the scene. He keeps claiming his friend was killed by a monster.
Nick and Hank (Russell Hornsby) meet up with Wu at the scene where they spot lots of empty beer cans and ammunition in the car. The driver, Ralph Rotterman (Mac Brandt), explains what happened and how he found his friend strangled by plants, stabbed by a root, and then hauled away by a tree monster. He agrees to take them to where he last saw his friend and watched him die. He describes the tree monster and how he shot it before running away. The body is gone, and Hank and Nick quietly discuss the investigation’s next steps.
Meanwhile, Rosalee, Monroe (Silas Weir Mitchell), and Eve (Bitsie Tulloch) return to the spice shop and Eve wants to see the hand mirror. Rosalee retrieves it from the drawer where she locked it up, and Eve is sure she broke it and it shattered into hundreds of pieces. It’s completely back together without a scratch, and Rosalee confirms it’s not magical and is in fact a family heirloom. They check it out and it starts dripping blood. Monroe snatches it up and returns it to the locked drawer. They wonder what Diana meant when she said it leads to the other place, and Eve thinks the only way to find out what’s going on is to go there.
Back at the station, Nick and Hank check out the driver and his missing friend, Dev, and find they have minor criminal histories. They try and figure out if Dev was Wesen or if maybe he and Ralph had a fight and Ralph shot him. Or, if there really was someone/something else out in the woods last night. Wu’s also been busy doing research and he’s learned three other people have gone missing in that area and their bodies were never recovered. All three went missing and left behind cars parked in the woods.
Nick and Hank interrogate Ralph and he sticks to his story. Ralph swears he didn’t do it and that he saw his friend get killed. Ralph finally admits he shot Dev, but quickly adds Dev was already dead when he fired his gun at the monster. Just then Wu interrupts the interrogation with news the blood on Ralph’s jacket wasn’t blood – it was chlorophyll. It was a substantially higher amount than usually found, and was actually the same amount as normally found in a giant tree.
Renard (Sasha Roiz) and Nick eyeball each other before Renard takes a video call from Dasha in his office. She says Diana drew an unusual set of ancient symbols, and Renard confesses Diana has more abilities than he and Adalind combined. Dasha thinks what Diana drew isn’t from her imagination and is very important. She admits she’s afraid of whatever this is Renard’s daughter is involved in.
Hank and Nick head over to research the tree monster at the spice shop. The fact the victim was poaching gives Rosalee an idea that maybe this Wesen was naturally wired to protect the environment. If you mess with their territory, they will mess you up. Hank finds a drawing of a Japanese Wesen who’s elusive and whose victims are lost to the forest for eternity. Hank thinks maybe this thing never woges and continuously defends its home, and Rosalee thinks that maybe it’s legal for this Wesen to kill to protect his home. The drawing of the creature looks like no Wesen any of Team Grimm have ever seen.
Back out in the forest, a woman illegally dumps chemicals out of the back of her truck. She pulls out a chair, prepared to stay a while until the job’s done.
Over at the station, Wu has discovered all the missing victims have a record of crimes against nature. Hank and Nick are close to being certain what they have on their hands is a Wesen Eco-Avenger (that’s not the technical term, but very descriptive nonetheless). They decide they’ll head back out to the woods in the morning.
Night falls and the woman dumping chemicals fell asleep next to her truck. She wakes up as branches grab her ankles and climb up her body, with a branch emerging through her mouth. The tree monster wraps her in its branches after she dies.
The next morning, Wu, Hank, and Nick trek through the woods in search of the tree monster. They split up and Wu spots a deer while Nick watches a bird soaring overhead. Hank spots squirrels playing in a tree and then Wu sees a pickup truck not far away. Nick’s walk through the woods leads him to an unusual-looking tree.
Wu checks out the G&K Waste Solutions truck and finds a bloody lawn chair next to it. He radios Nick and Hank to let them know he’s found a truck dumping toxic waste and a bloody chair. The smell’s horrible, and Nick notices the blood isn’t dry yet.
Hank, Nick, and Wu return to the station and find the truck’s driver has a police record for dumping toxic waste on public lands. They map out where all of the missing people were last seen, and mark an X in the center of the circle that’s formed by the locations.
Once more we’re back in the forest at the base of the tree Nick spotted earlier that morning. They all get a weird vibe from the tree and they find blood at the tree’s base. Hank then points out a man’s face, screaming, in the tree trunk. They find even more screaming faces throughout the tree and Hank says, “This gives a whole new meaning to family tree.”
Team Grimm meets up at the spice shop and Rosalee says she’s heard of this kind of tree before. They match the faces of the missing people to the faces in the tree and Monroe’s astounded this could happen. Rosalee thinks the tree absorbed them into itself. They figure out the tree monster kills those who hurt the woods and feeds them to the tree, meaning they’re working together to keep the forest clean. They now have the tree, but catching the tree monster will be more difficult. Rosalee has an idea to whip up a batch of something that will pass as a toxic substitute causing the tree monster to reveal itself. It’s pretty difficult to make and Rosalee and Monroe get right on it while Hank, Wu, and Monroe find sharp weapons to deal with the tree monster.
Back in the woods, Monroe gets his first look at the blood-sucking tree. Hank, Wu, Nick, and Monroe spread out the toxin substitute Rosalee brewed up and wait to be attacked. And, the wait’s a long one…so long in fact that Monroe calls Rosalee to see if there’s a way to spike the toxic up a notch. She suggests turpentine and volunteers to bring it to them.
Monroe’s still not sure they should be trying to get rid of the tree monster and the blood-sucking tree the monster feeds. After all, they’re protecting the forest.
Rosalee’s about half a mile from meeting up with the team when she hits something in the road and begins leaking oil. Her car breaks down and she gets out and finally notices the oil leak. Monroe calls to check up on her and hears Rosalee scream after he tells her he’s on his way to her location.
Rosalee runs through the woods while Monroe and the team head to her location. They make it to her before she’s attacked, and she warns them it was right behind her. Rosalee then gets her first look at the blood-sucking tree and says it’s beautiful which is, of course, when branches grab her and pull her toward it. The gang fight it off, chopping at the branches and freeing Rosalee. The tree monster approaches and Nick tells it he’s a Grimm, but that doesn’t go over well. The tree monster attacks all of them with its branches but Nick’s able to chop it where a heart would be if it was a person. It slumps to the ground, oozing green blood and then is pulled into the blood-sucking tree. Its face appears on the trunk, and Monroe’s changed his tune and wants to chop the whole thing down and make it into firewood. They can’t arrest a tree so case closed. As they drive away, the tree monster opens its eyes.
Monroe and Rosalee climb into bed, with Monroe warning his wife she shouldn’t go on any more adventures like that until after the babies are born. As he’s about to turn off the light, they look up at the ceiling and see a crude pattern in the wood that looks like two eyes and a mouth. They immediately decide they should paint their ceiling.