Can't open mission 7 \ "Overdose \" (Assassin's Creed: Syndicate)

The seventh quest is the DLC. To open it, you must have installed the Darwin and Dickens Conspiracy add-on, and you must also complete all the tasks of Dickens and Darwin.

And how to follow the plot then? Where to? I only have Dickens' marks.

Go through the plot further, you will meet Darwin, and after passing this plot part, missions with him open up.

In addition to the above, Darwin appears in 4 parts, 2 memories, and missions will open after 4 memories of this part.

And yet - this is not a DLS, but a storyline (there are everywhere in the walkthroughs).

I am already in the fourth part and passed part of Darwin's tasks. And the "overdose" does not appear.

Completed several levels on the train and voila! The "overdose" has opened. What's the glitch?

At the beginning I passed the train, then Dickens, and then this part of the plot, these missions opened. Along the way, this is not a glitch.