#1 - Sept. 5, 2017, 2:11 p.m.
When can I use relics in the crucible?
#4 - Sept. 5, 2017, 3:06 p.m.
The storyline and features in Argus are unlocking on a week by week basis, we've got a preview of that up here in this News article:
Patch 7.3 Preview: The Campaign for Argus
Week 3 is when the Netherlight Crucible will be fully unlocked after the storyline is finished there :)
We're just about to go into Week 2 now tomorrow (Wednesday 6th September).
Hope this helps :)