Before Guilliman awakened.
Calgar could never allow even the slightest hint of this news to leak out, because even the smallest leak would draw unpredictable enemies—and traitors' attention—to Ultramar.
Before awakening Guilliman, he still had to confirm the other party's identity. If they were merely Fallen Angels,
then there was a high chance their words could not be trusted.
After all, they were traitors from the Dark Angels Chapter.
But.
If they were not merely Fallen Angels, but also had their Primarch, Lion El'Jonson, behind them, then they might truly possess a way to save Guilliman.
After all, surely a Primarch would not speak falsely?
At present, their dealings with Gamma World were still underway.
They hoped Gamma World could build more Gravity Slingshots for them, perhaps even become a supplier for some of their equipment.
They valued the gravitational technology used by Gamma World.
Though they resisted heretical technology, if it was genuinely useful, they were absolutely unwilling to reject it. While some rigidly pursued the loyalty described in the Codex Astartes,
war was not always unchanging.
Long ago, their Primarch had personally repudiated certain tenets he had established, telling others that the Primarch's codex was not entirely correct either.
Later, the Codex Astartes rose to prominence again because the disasters brought by the Horus Heresy required it to restrain the power of certain Chapters, preventing the Astartes from expanding too greatly in size or becoming excessively powerful.
However, such things were no longer suited to the current era.
Yet for many straightforward Ultramarines, they still blindly revered the Codex Astartes, treating it as an absolutely pure faith. Those excessive fixations were, in truth, somewhat related to Calgar as well, but matters had now grown too unwieldy to turn around.
Therefore, perhaps only a Primarch was qualified to amend