So we know the Moebian 6th fell to serving Nurgle on Nox Alpha, converting due to the influence of The Stranger. The Stranger appears to have come from the uprising side of the Nox Alpha war, so not already among Imperial forces. Obviously, the Moebian 6th supported the activities of the Cult of Admonition once they reached Tertium, but their change of allegiance against the Imperium remained hidden until they actively turned against Imperial command in Tertium.
So…how did they keep their allegiance hidden from the crew of the voidship which carried them back to Tertium? Or did they take control of the voidship? Or was the crew of the voidship already turned to the same cause? And where is the voidship now?
In the future might we expect reinforcements for the Scabs & Dregs to arrive from Nox Alpha, aboard a hostile voidship?