Harold Drake is the Whitechapel Templar hunt: an illegal-goods trader running a black market in the heart of the borough with the Order's blessing. Kill him with a crate of dynamite for full sync.
Drake and an accomplice are handing out the last dozen crates of dynamite meant to arm every Blighter in London. The dynamite he is so careful with is exactly what the challenge asks you to use against him.
The first borough the Fryes free has one of each activity: Drake's hunt, the bounty on Homer Dalton, the Spitalfields stronghold and the Radclyffe Mill factory.
Drake and his helper are standing beside the dynamite crates. Set off one of the crates beside him so the explosion does the killing. A blade or a plain gunshot to Drake himself will not meet the condition.
Argus and Rose Bartlett
Argus and Rose Bartlett is a Templar hunt in The Strand against the owners of the Bed and Bottle, a pub and lodging house linked to several missing-person cases. Perform a cover kill on one of them for full sync.
Beatrice Gribble
Beatrice Gribble is a Westminster Templar hunt against a would-be lady-in-waiting who, after repeated rejections, has told the Templars she plans to kill the Queen's consort. Kill her with a voltaic bomb for full sync.
Captain Hargrave II
Captain Hargrave II is a Templar hunt on The Thames against Samuel Hargrave, who killed his father years ago and took over his identity and post patrolling the river for the Templars. Kill him and throw the body in the Thames for full sync.
Edgar Collicott and Bodyguard
Edgar Collicott and Bodyguard is a Westminster Templar hunt against the Order's most trusted messenger, who handles its 'special operations' of stealing secrets and silencing the sources. Air assassinate him for full sync.