The follow-up spread was a naval combat tactic commonly used by the military of the Chiss Ascendancy, a nation-state of the Chiss species in the Unknown Regions. Chiss warships were equipped with breacher missiles that delivered a payload of acid to weaken enemy hulls and electronics, as well as spectrum lasers. Spectrum lasers were a type of laser weapon that automatically modulated its laser frequency to maximize damage to the substance being targeted, and their output was higher on areas of hull hit by breacher acid. As a result, the follow-up spread was used as a common Chiss battle tactic.
At the Springhawks skirmish against the HopeBreaker over the planet "Sunrise," the Chiss ship was attacked by unidentified enemies. Senior Captain Mitth'raw'nuruodo "Thrawn" employed the follow-up spread against them, seeking to learn how well those foes knew the Chiss' preferred tactics.
The Chiss follow-up spread first appeared in Timothy Zahn's 2019 novel Thrawn: Treason, the final installment of the Canon Thrawn trilogy. It was first identified by name in Zahn's 2021 novel Thrawn Ascendancy: Greater Good, the second book of his Star Wars: The Ascendancy Trilogy.
The Chiss follow-up spread first appeared in Timothy Zahn's 2019 novel Thrawn: Treason, the final installment of the Canon Thrawn trilogy. It was first identified by name in Zahn's 2021 novel Thrawn Ascendancy: Greater Good, the second book of his Star Wars: The Ascendancy Trilogy.