Ciri’s Story: Breakneck Speed is the Ciri flashback told by Dandelion after he is rescued in A Poet Under Pressure. It picks up right after Ciri beat Whoreson Junior and freed Dudu. Junior sounds the alarm, and Ciri and Dandelion have to ride for their lives through the streets of Novigrad.
The player takes Ciri on a mad chase through the city, with Junior’s henchmen on every corner and the Temple Guard joining in. The only escape route leads to Temple Isle, and there the trap closes. With every path cut off, Ciri has no choice but to use her power and teleport away. Dandelion stays behind, puts up what he insists was a very brave fight, and ends up in a cell.
The flashback fills in the last gap in the Novigrad story: it explains why Ciri vanished from the city and why Dandelion ended up in prison. After this, Geralt has enough pieces to start looking for Ciri elsewhere.