Appearing in 1st story
- Spider-Man (Peter Parker) (Possessed by a symbiote) (Released from control)
- Storm (Ororo Munroe)
- Marvel Girl (Rachel Grey)
- Beast (Hank McCoy)
- Firestar (Angie Jones)
- Iceman (Bobby Drake)
- Dr. Cecilia Reyes (Mentioned)
- Brood—Symbiote Imperium (Named only)
- Mr. Sinister (Nathan Essex) (Cameo)
- Venom Symbiote (Mentioned)
- Beyonder (Mentioned)
- Emperor Vulcan (Gabriel Summers) (Mentioned)
- Deathbird's unborn child (Mentioned)
- Earth Orbit
- Battleworld (Mentioned)
Synopsis for 1st story
As a symbiote-possessed swarm of Brood led by Deathbird exit the Bamfgate and battle the X-Men, Spider-Man and Beast cross-check each others' extraterrestrial enemies, while the Special Class, Rachel Summers, and Storm engage the aliens while arguing over who the mole is. Julian Keller accuses Robert Herman of being the mole, despite his protests. Spider-Man explains the symbiotes are weak to intense heat, asking if the brood are empowered by flames. Firestar unleashes a torrent of fire, and Deathbird orders a retreat.
In the aftermath of the skirmish, Storm expresses confusion as to why Deathbird would turn against S.W.O.R.D., and Spider-Man explains that the symbiotes are nearly invincible aside from flames and sonics, and that they take over their hosts, turning them into monsters, something he has firsthand experience with having once worn one himself. Rachel Summers seizes on this and accuses him of allying with the aliens, still angry that Martha erased part of her memory. Beast breaks up the fight, determined to save his girlfriend, and tells Spider-Man to accompany him since he has experience fighting symbiotes. The Special Class accompanies them, ignoring Storm's order to stop. On S.W.O.R.D's space station, they are attacked by a swarm of symbiote-controlled Brood, and Santo Vaccarro smashes the Bamfgate to keep them from getting through, inadvertently trapping them on the station. While the students bicker, Beast asks Spider-Man how the symbiotes got into the space station, and Peter quips that they tend to infest things in space the way rats infest places in New York, revealing how he acquired the Venom symbiote. Trevor Hawkins remarks that the symbiote-Brood seem to be getting weaker, and Spider-Man states the symbiotes tend to drain their hosts' vitality and need new ones. As the symbiotes detach from the Brood and advance towards the X-Men, Hellion contains them in a force field.
They are immediately attacked by a symbiote-controlled Abigail Brand, who Beast engages while Spider-Man leads the students deeper into the facility. Irritated that the others think he's the mole, Glob remarks that wearing a symbiote would be like wearing a skin and jokingly remarks that he could kill Hellion and take one to not be a freak anymore, but that he won't since he's not the spy. They come across symbiote-controlled S.W.O.R.D agents devouring the Brood, who immediately pursue them. Ernst reveals the symbiotes are herding them towards Deathbird, who is surrounded by a swarm of host-less symbiotes. Spider-Man tries to appeal to Deathbird to fight the symbiote's control, but when that fails he sticks his hand into Hellion's force field and allows one of the symbiotes inside to bond with him, asking No-Girl to prove she's not the mole by helping him control it. While the symbiote-augmented Spider-Man grapples with Deathbird, No-Girl battles the symbiote's will in his subconscious. Ernst complains how unfair it is that Spider-Man suspects No-Girl is the mole, while Iara and Santo continue to suspect Robert.
As the symbiote bonded to him washes over No-Girl like a tsunami, Spider-Man tells Deathbird that the Brood were deceived and devoured by the symbiotes, and appeals to her to resist the creature for the sake of her unborn child. Deathbird forces the symbiote off her and Hellion contains it. No-Girl is expelled from Peter's mind and the symbiote bonded to Spider-Man takes over him, but just as he is about to attack his students Beast blasts the parasite off of him and Hellion contains it. A single Bamf, still controlled by a symbiote, manages to teleport away.
Abigail states they'll dispose of the symbiotes by expelling them from the airlock, but reveals the symbiotes destroyed their ships, leaving only the ship-to-ship pods - which lack heat shielding - intact. Glob volunteers to act as a heat-shield, impressing Spider-Man with his bravery. His body successfully absorbs the brunt of the heat generated by re-entry, but at first it looks like he perished in the impact, though he gives them a thumbs-up as a sign he survived.
Back at the academy, the other members of the Special Class lament that they suspected him, and Peter calls No-Girl into his office. He tells her that erasing Rachel Summers' memory makes her a suspect but thanks her for her assistance, then outright asks for her to tell him if she's the mole.
Spider-Man's Spider-Sense goes off as a voice behind him abruptly interrupts, stating that Martha cannot be the mole. He turns to see Ernst, who confesses to being the mole, accompanied by none other than Mr. Sinister.
• Field Trip! Spider-Man and the X-kids blast into space to take down Deathbird’s Brood-Symbiote Imperium!
• Glob Herman’s finest hour!
• And the mole’s identity revealed! Maybe we should have led with that one!
- Spider-Man states that all symbiotes don't set off his Spider-Sense, something that was previously only applicable to the Venom symbiote and its progeny, though this may be because they are the only symbiotes who he has any experience with.
- The symbiote Peter temporarily bonds to takes on an appearance identical to the Venom Symbiote.
- Symbiote/Brood hybrids had previously appeared in the alternate universe of Space: Punisher.