What the achievement asks
Complete the Tides of Vengeance war campaign. Ten points, account-wide, Horde only.
Four chapters, released as patch 8.1's continuation of the war. This is the Horde side; the Alliance has its own version of the same patch under the same name, with entirely different chapters.
The four chapters
They arrive in order, and they took weeks originally
Tides of Vengeance was released in stages, a chapter at a time over several weeks. That gating is long gone: a character coming to it now can run all four back to back.
What has not gone away is the ordering. The chapters are sequential and each one has to be finished before the next appears.
What has to be done first
The war campaign builds on the Zandalar story rather than running alongside it:
- Welcome to Zandalar, which opens the continent
- The three zone stories, The Throne of Zuldazar, The Dark Heart of Nazmir and Secrets in the Sands
- The first half of the war campaign, including A Bargain of Blood and The Final Seal
If the first chapter is not offered, one of those is unfinished. The war campaign gives no explanation when it declines to continue.