Defamation is a short Charles Darwin memory: Darwin asks you to fetch him a newspaper, and you find a Blighter bullying the newsboy. A foot chase follows, and the thug's leaflet shows that someone is paying to spread attacks on Darwin.
Part 3 of 6 in Charles Darwin's London Stories
Walk to the street vendor, stop the Blighter harassing him and chase the thug through crowded streets with obstacles in the way. Tackle him and question him. He says a man paid his gang to make newsboys display a particular leaflet, and hands it over.
Talk to Darwin, go to the newspaper vendor, chase the Blighter, tackle and interrogate him and take the leaflet.
Even if you get within reach early, the game does not let you tackle the thug until the train is about to hit him, so the rescue always happens at the last moment.
The thug always has a head start and runs for the railway. You cannot tackle him until the train is almost on him, so focus on keeping him in sight past the obstacles rather than trying to bring him down early. If you already know his route, you can cut corners and intercept him sooner.
The paper Darwin wants carries a rebuttal of Richard Owen, the rival Jacob scared into naming Elliotson in On the Origin of Syrup. The leaflet you take from the thug is the first proof of a paid campaign against Darwin, which Cruel Caricature follows back to its print shop.
A Struggle for Existence
A Struggle for Existence is the fifth Charles Darwin memory: Florence Nightingale tells you a policeman has hauled Darwin away, and the two of you go after him. You kidnap the officer for answers, then fight through a Templar hideout while Nightingale treats Darwin.
An Abominable Mystery
An Abominable Mystery is the second Charles Darwin memory: a plant no botanist recognises is making people in a Westminster park delirious. You investigate the flower beds, follow tracks to a cart full of the plants and then use their pollen against pursuers while driving Darwin to a safe disposal spot.
Cruel Caricature
Cruel Caricature is the fourth Charles Darwin memory: posters showing Darwin as an ape under the slogan "We are not apes" are going up around London. You tear them down, catch a billposter and follow the trail to an underground print shop that you blow up.
Darwin's Orchid
Darwin's Orchid is a short Charles Darwin memory from The Darwin and Dickens Conspiracy: a rare orchid from Madagascar is waiting for Darwin at the docks, and a rival has sent thugs to take it first. You race across the river, grab the flower off a boat and bring it back.