Transformers #23 artist Alex Milne has posted up hi-resolution covers of his dueling covers from the upcoming book, slated for release next Wednesday.
Variant A shows the right-hand side of present-day Optimus Prime's face, while variant B shows the left-hand of the past Optimus Prime (aka Orion Pax).
This issue will serve as a prelude to Chaos, which begins with Mike Costa and Livio Ramondelli's Transformers #24.
In this issue, Optimus Prime recounts the fascinating end of his and Megatron's initial meeting as he decides the fate of the jailed Megatron.
James Roberts wrote this issue and Alex Milne did the art, with Josh Perez on colors for the covers.
See the combined cover below.

