The Key of Osanalan is a fictitious Forerunner object underneath the city of Cleveland, Ohio on Earth.[1] Colonel James Ackerson said that without the Key, the Halos will not properly activate.
However, the key does not exist at all in 2552, but rather existed at an earlier date. During their childhood, James Ackerson and his brother, Ruwan, made up an object called the Key of Osanalan for their make-believe games.[2] It is likely Ackerson told the Covenant about the key to prevent them from simply destroying Cleveland.
After agreeing to give the Covenant their "Key", Ruwan informed them that he was in fact the key, and then told the Minister of Inquisition to "kiss my ass". [3]
The ruse behind the key's true status lasted long enough for UNSC forces to destroy most of the Covenant forces in Cleveland, potentially saving the remnants of the city.
While the Key was used as a ruse by Ruwan and the UNSC, the true Key of Osanalan from the Ackerson's childhood was a simple skeleton key fashioned from what appears to be tin-foil. The Key's intention was to rescue the "Princess" of their game; a possible foreshadowing to Ruwan meeting Myras Tyla.
After the events on the Harbinger of Piety, James Ackerson openly mocked the Covenant about the key's non-existence, which ended in his death. [4]
Trivia
- Ironically, like all Reclaimers, if given the opportunity Ruwan could indeed activate the Halo rings, acting as a "Key" for the Installations.
- While Ruwan seemed to say that he opened Halo, he was in fact answering the Minister's question of "Tell us what you know of the Halo?". The comic boxes read in order from left to right, then descend to the next lower row.