Toxicity is the forty-first episode of Transformers: Prime.
Bulkhead encounters life-threatening danger during the last relic hunt.
With other teams dispatched to find the other Iacon relics, Megatron visits the Insecticon hive in the Nemesis and calls for a volunteer. A voice tells Megatron that there was no greater ferocity than an Insecticon hive. An Insecticon lands on the panel behind Megatron and revealed himself as Hardshell. Megatron sends him and three other Insecticons to find the fourth and final relic. Megatron also orders Hardshell to annihilate anything that gets in their way.
The four Insecticons arrive at a volcanic region on the equator. Hardshell ordered them to divide, which they immediately split up.
At the Autobot base, Bulkhead watches Miko leave with her team before he is dispatched to the area at the equator. Bulkhead tells Bumblebee to take care of Miko and Raf tells Miko to take care of Bumblebee. Optimus tells Bulkhead to prepare to leave and Bulkhead said he was prepping for tropical weather "Wrecker Style." Though he arrives at the correct coordinates, there's no relic around. As he continues forward, he was swiftly grabbed in the air by Hardshell and thrown on the ground. The Insecticon attacks Bulkhead and, after a brief exchange of words, the pair fight. Although Bulkhead takes a few major hits, the Wrecker flattens Hardshell, knocking a mandible off the Insecticon in the process and leaving Hardshell unconscious. Bulkhead then heads downhill, realizing that an old lava flow may have taken the relic in the same direction. He keeps Agent Fowler updated back at base via radio.
Meanwhile, Hardshell comes to as the other three Insecticons fly around him. He states in low tone that Bulkhead made a grave mistake leaving him alive and that will be the last mistake he will ever make. Hardshell and the Insecticons head off with the other Insecticons to find their target.
Though leaking energon from his recent fight, Bulkhead manages to find the relic just in time. Unfortunately, it turns out to be a toxic form of Energon known as Tox-En, which Megatron could refine into a lethal bio-weapon. Though Fowler suggests bringing it to base, Bulkhead realizes that it can harm the other Autobots as well. Bulkhead decides that he is going to have to dispose of it himself,"Wrecker style".
Hardshell and the other Insecticons find the vessel abandoned. They transform and as one of them goes to the container and grabs the small piece of Tox-En within, the grenade Bulkhead had left behind explodes, leaving the Insecticon fatally riddled with Tox-En shrapnel. Hardshell sees this and slowly backs away. Hardshell lets Megatron know about the Tox-En, but Megatron wants to know why Hardshell doesn't have the stuff yet.
Bulkhead, meanwhile, runs away from the volcano with the rest of the Tox-En, leaving a trail of leaking energon to throw off the Insecticons. As he turns and starts to head up the volcano, Bulkhead strikes up a conversation with Fowler about their past war-time careers and discovers they've more in common than they'd previously thought. However, as Bulkhead continues his journey, he begins to feel the effects of the toxic energon and almost succumbs to its spark-sapping properties. After Agent Fowler convinces him to keep going for the sake of duty and family, mostly Miko as well, Bulkhead trudges on.
Meanwhile, Hardshell figures out the false trail and he goes with the other two Insecticons to fly uphill.
They catch up to Bulkhead, who has just arrived at the volcano's mouth, and surrounded him. Bulkhead throws a grenade at one Insecticon and jabs the Tox-En directly towards Hardshell when the Insecticon charged. The third Insecticon charges in bug mode, but Bulkhead decks it with the Tox-En and jabs the chunk into its shell before turning back to face Hardshell. Receiving the news that Miko is safe, Bulkhead begins sparring with Hardshell, though they are both now weakened from the toxic energon. Though Hardshell manages to get the better of Bulkhead, as he moves to finish the Wrecker off, Bulkhead works up the strength to throw Hardshell over to the Tox-En before flinging the monster towards a hole in the caldera crust leading down into the molten lava. Bulkhead then throws the Tox-En to Hardshell, and the dizzied Insecticon falls into the volcano, destroying the toxic relic.
As Bulkhead heads for the Ground Bridge, Hardshell climbs out of the volcano and shoots the Autobot in the back, sending him flying through the Ground Bridge to land within the Autobot base, his back burning. Ratchet, Raf, and Fowler see the smoke coming out of Bulkhead and run to his aid.
Main Article: Toxicity Gallery
- Bulkhead flashes back to scenes from previous episodes when Fowler is trying to get him to continue the mission. First, he remembers several instances where his life was threatened, including:
- Leading Scraplets through the Ground Bridge into the Arctic in "Scrapheap".
- Getting his Energon drained by the energon harvester in "Deus ex Machina".
- Clashing with Breakdown in "Out of His Head".
- Getting blown back by the malfunctioning Ground Bridge in "Shadowzone".
- Protecting Miko from falling rocks in "Rock Bottom".
- Clashing with Breakdown in "Operation: Breakdown".
- Being wired to one of Dreadwing's bombs in "Loose Cannons".
- Getting attacked by Scraplets in "Scrapheap".
- Hardshell makes his debut.
- Shortly after the above, Bulkhead remembers several interactions with Miko, including:
- Miko assuring him that she's protected before Bulkhead heads down a slope in "Darkness Rising, Part 3".
- Bulkhead showing Miko a new battle scar in "Metal Attraction".
- Miko revealing herself from inside Bulkhead's chest in "Darkness Rising, Part 4".
- Bulkhead trying to dissuade Miko from using him as a role model in "Deus ex Machina".
- An exhausted Miko trying to clear rubble in "Rock Bottom".
- Miko trying to get an amnesiac Bulkhead to remember her in "T.M.I.".
- Bulkhead's tactic of hiding a grenade in the Tox-En container is similar to the one proposed by Wheeljack in "Triage". Wrecker style, indeed.
- Apparently, Bulkhead has been inside Decepticon barracks at some point (possibly on a mission for the Wreckers back on Cybertron). They are very, very smelly, but not as much as the landscape near an active volcano.
- In the past, the Wreckers have generally been a small, closely knit unit (despite their horrific attrition rates). However, Hardshell's comment that he's faced Wreckers numerous times suggests the team is much larger in the Aligned continuity.
- Bulkhead tells Fowler that the relic would likely survive a dip in molten rock while hunting for it in a cooled lava flow. Not only is this technically untrue (the Tox-En only survived its fall due to its container), but a drop into lava is exactly how Bulkhead disposes of the relic in the end.
- Despite having at least one more grenade on his person, Bulkhead doesn't attempt to leave the entire Tox-En cache in his Insecticon trap. Presumably, it wouldn't have been enough to completely destroy the toxic fuel, or it wouldn't have fit in the canister, giving Hardshell's team warning that something was up.
- Bulkhead finally finds something even worse than Scraplets. Incidentally, he saw the effects of both Scraplets and Tox-En during the war, and neither was a pleasant experience.
- Assuming Tox-En is the robot equivalent of mustard gas or a bioweapon, its use would be a war crime according to human conventions. Bulkhead quite rightly wants to destroy it, but that doesn't stop him from using it several times. This is the second episode in a row where the Autobots do something very ethically questionable in pursuit of the relics.