[This is a review of Teen Wolf season 3, episode 20. It contains SPOILERS.]

You know that it’s about to get real in Teen Wolf when a viewer discretion warning pops up. It’s a show that regularly skewers, bludgeons and eviscerates its characters in gory detail, but this is the episode that called for special consideration. ‘Echo House’ contains themes including but not limited to: amphetamine abuse, suicide, schizophrenia, psychiatric malpractice, trepanation and illicit basement sex. You have been warned.

Speaking of skewering and eviscerating, Stiles is suffering some guilt issues over literally twisting the knife in his best friend’s stomach during last week’s episode, and while the nogitsune is temporarily dormant he makes the decision to have himself committed. Where better to go, of course, than Eichen House: the mental institution that also happened to be the setting for his most recent nightmare.

Teen Wolf has been playing a challenging game during this half of the season by mixing up the supernatural elements with real-world issues, the biggest of which is terminal illness. In addition to the Japanese fox spirit possessing him, Stiles is also suffering from frontotemporal dementia, a severe neurodegenerative disease that leaves him with, at best, about ten years to live.

In ‘Echo House,’ the mature theme of the week is mental illness and life inside a psychiatric institute. Given the limited running time for the episode and the amount of supernatural craziness going on, this was probably never going to be an equivalent of the House two-parter ‘Broken,’ but even so this feels like a rather superficial depiction. There’s a suicide on Stiles’ first night, a male version of Nurse Ratched to leer at the patients and a brief counselling session that ends with the counsellor telling Stiles she intends to give him a lethal injection. Clearly she skipped a few classes while training for the job.

As mentioned earlier, Stiles also gets to lose his virginity in this episode. It happens more or less out of nowhere and is over pretty quickly, without much fanfare. It is, therefore, a pretty accurate portrayal of teenage sex. The post-coital afterglow is spoiled when he and his newly-acquired paramour, Malia Tate, discover a body hidden inside the basement wall that appears to belong to… the nogitsune? Either the ancient fox spirit is actually just a regular ghost or the body belongs to one of its previous hosts; this part is still a little unclear.

Back in the outside world, Scott and co. get handed a task to keep them busy while the rest of the plot is progressing. It transpires that the deceased yakuza Silverfinger was secretly using his eponymous appendage as storage space for a tiny scroll with handy tips on how to fight a nogitsune. To retrieve it, all the gang needs to do is to take down an armored FBI van that contains evidence from Silverfinger’s murder. After demonstrating her skill with a sword to Scott, Kira is permitted to come along for the ride, though she shows up without either her skills or her sword and doesn’t do much aside from getting roughed up a little.

The detours into other parts of Beacon Hills really are the weaker aspect of ‘Echo House,’ largely because it felt like writer Jeff Davis was struggling to come up with things for the other characters to do. This is true for no one more than poor Derek Hale, who has been noticeably floundering during the second half of this season and tagging along with other characters’ storylines in lieu of being given one of his own. In ‘Echo House’ he’s permitted only one short scene in which he helps with Chris Argent’s character development. If, as the latest preview suggests, a main character is going to get killed off this season, it’s hard not to wonder if Davis is about to give up on Derek entirely.

Teen Wolf returns next Monday with ‘The Fox and the Wolf’ on MTV @10pm. Watch the promo below.