This week’s episode starts with Arrow putting Roy through his paces whilst  an old foe of Arrow’s, Turner, staging a particularly gruesome jailbreak.  Meanwhile, pesky Quentin is busy trying to force Laurel to go to an AA meeting but she isn’t playing ball.  Felicity tells Arrow that Turner has broken into an architect’s house, ransacking it and stealing some blueprints for Malcolm Merlyn’s house.  Arrow realizes with a gasp that what Turner is after is a prototype for an earthquake machine that Merlyn designed, which has the potential to kill thousands.  He rushes to Merlin’s house with Roy in tow, fresh from training.  There’s a confrontation, and whilst Arrow is holding Roy off from killing one of Turner’s cohorts, Turner is escaping with the machine.  Arrow is angry with Roy that his temper bested him again, but at the same time he’s guilty about what happened with Slade and he wants to somehow make amends through Roy.  There’s a flashback to Sarah and Oliver on the island, looking for Slade’s cave and stumbling upon his plans to bomb a freighter to take revenge on Ivo for Shado’s death.  They manage to talk Slade out of the bombing but he is evidently broken.

Back in Starling city, Moira goes out with Walter, who is not fond of Sebastian Blood, and persuades Moira to run against him for mayor.  Times are tough on Laurel, who finds out that the Bar is starting disciplinary proceedings against her.  Felicity runs a fingerprint at Merlin’s house and traces it back to one Milo Armitrage: an international arms dealer, natch.  He’s the one Turner has been working for and he’s trying to sell the earthquake machine to the highest bidder.  Arrow speeds to the docks to intercept his boat before he can make off with the machine.  There’s a confrontation with Milo and Turner, and Roy arrives at the crucial moment.  Arrow has to take his hood off to persuade Roy to find his humanity and lend some muscle.  Roy beats the machine to a pulp, but now Oliver has no choice but to take Roy into his full confidence.  Is this the beginning of a formidable crime fighting partnership?  Tune in next week to find out.