"Failed Experiments" is the nineteenth episode of the third season of ABC's Agents of S.H.I.E.L.D. and the sixty-third episode of the series overall. It aired on May 3, 2016. It was written by Brent Fletcher and directed by Wendey Stanzler.
Radcliffe's first attempt to turn humans into Inhumans fails when the Hydra operatives used as test subjects die, and he realises that living Kree blood is needed. Wanting her friends at SHIELD to feel what she is feeling while under Hive's control, Daisy suggests to him that they turn the agents into Inhumans once Radcliffe's experiments succeed. Hive is concerned that Daisy still cares about her human friends, worrying she will not be able to fight them if necessary.
Fitz and Simmons create a potential cure for Hive's infection, but it could destroy the immune system of an Inhuman it is used on. Lincoln offers to be a test subject, but Coulson forbids him. However he later injects himself with the antitoxin anyway, leaving him severely weakened, while proving it would not work against Hive's infection. His immune system having shut down, Lincoln is put in quarantine until he recovers.
Daisy is caught on surveillance by SHIELD, revealing Hive's location to them, but while Mack believes she is resisting the enthrallment and trying to contact SHIELD for help, Coulson suspects a trap. He sends a team led by May and Mack to infiltrate the town and assassinate Hive, and May poses as a Hydra operative to trick James into revealing Hive's whereabouts. The team find the Kree artifact, revealed to be a beacon, which Hive is using to signal to a meteor orbiting Earth. The meteor crashes in the town, and two Kree Reapers, who have been cryogenically preserved inside for over a thousand years, emerge and begin hunting for Inhumans, having been put in orbit by their masters as a fail-safe in case the Inhumans rebelled against them.
One of the Reapers attacks Hive, who eventually kills him in a fight, after which the SHIELD team attempt to destroy Hive with a grenade launcher, which proves insufficient. The other Kree kills Alisha before Daisy incapacitates him, and Radcliffe begins draining his blood. Mack approaches Daisy and tries to convince her to leave with him, still believing she is resisting Hive's control, but she denies it and reveals Hive's plan to transform humankind. Mack then vaporizes the captured Kree with a Hydra splinter bomb, and a livid Daisy attacks him, subduing him with her powers and beating him savagely. May shoots her to save Mack, and the SHIELD agents escape while Radcliffe tends to Hive and Daisy's injuries. Realizing there is Kree blood inside her from the GH325 injected into her after she was shot by Ian Quinn, Daisy offers to let her blood be harvested.