An incursor being launched
The Incursor was a Vau N'Akat weapon carried by Rev-1-type warships. It was developed from knowledge forcibly extracted from Wesley Crusher by Asencia, following his capture in 2384. Shortly after impacting its target, the weapon generated an expanding blast wave of exotic temporal radiation that rapidly aged everything caught within it.
In 2384, the Rev-1 fired its Incursor at the USS Voyager-A, having powered it from Voyager via an energy drain. The Incursor breached Shuttlebay 3 and activated, inflicting near-fatal aging to Commander Tysess, although The Doctor was able to reverse the aging using Cerberusian gene therapy. Vice Admiral Kathryn Janeway managed to slow the progress of the weapon via a level-10 containment field remodulated to its emissions, but this bought only a temporary reprieve.
Zero volunteered to enter the field and deal with the weapon, as their Medusan nature would afford them some protection from its effects. However, they found that the Incursor could not be deactivated, only reprogrammed to target another Starfleet vessel. Cadet Maj'el proposed that her Nova Flyer be the new target; she and the rest of Nova Squadron proceeded to lead the Incursor into a collision course with the Rev-1, destroying the ship. Exposure to the Incursor caused critical deterioration to Zero's already failing humanoid body, necessitating their transfer to a new containment suit constructed by Jankom Pog using the USS Protostar's vehicle replicator. (PRO: "Ascension, Part II")