Episode 1: A New Hope
At the end of last season, Walter Sykes (a nutcase whose soul had been tainted by an artifact as a kid) was disintegrated trying to get through a portal, but left a bomb in his wheelchair that blew up the warehouse and everything in it … except Myka, Pete, and Artie, who were saved when H.G. Wells sacrificed herself to erect a force field that protected them from the explosion. Pete figured Sykes had won after all, since he destroyed the Warehouse, but Artie pulled out a pocket watch (left to him by James MacPherson) and said they weren’t beaten yet.
This episode opens with the trio standing in the ruins of the Warehouse and wondering what to do. Myka hopes the watch can reconstitute the Warehouse, but Artie says he’s not exactly sure what the watch does. He
thinks it might lead them to an artifact, which might be able to bring back the warehouse, but he’s not sure. Pete says all he can think about is how sad he is and Artie freaks out, running through the rubble to where the Ytterbium Chamber used to be. When Artie sees the Chamber has been destroyed, he says they have to get to a TV right away. At the boardinghouse, they learn about Mrs. Frederick’s death (she expired with the Warehouse, since they were psychically connected), and Leena and Claudia learn about the Warehouse’s destruction. (In case you’re wondering, Trayler, the dog, is fine … he comes into the boardinghouse hale and hearty.)
They ask Artie about the watch again, but Myka seems to have changed her tune; now she thinks using the watch might have a downside (as all artifacts 
do), so she doesn’t want them to act without considering the consequences. Claudia says it doesn’t much matter and lists the death toll. Myka says people die, sometimes people you love (anyone else think she means Wells?), but they can’t let that push them into making selfish decisions. Leena notices the pall that’s fallen over everyone and asks about the Ytterbium Chamber. Turns out that’s where Pandora’s Box was kept, so when Artie turns on the TV the news is full of stock market crashes, riots, and mass suicides. The only thing left in Pandora’s Box was hope, so when the Warehouse was destroyed, the world lost hope.
Artie examines the watch and finds the word Barbosa on the face (where’s Jack Sparrow when you need him?) and some Portuguese on the back. Myka translates it (which surprises them for some reason) and when Artie pushes
the button, the watch glows and turns into a stopwatch that’s counting down from 24 hours—actually, it’s 23 hours, since they’ve already wasted an hour from when the Warehouse blew up. Artie figures they have 23 hours to find whatever artifact they need to reverse time and save the Warehouse; the problem is, it could be anywhere in the world. (Pete: “I like beavers, I’ll take Canada.”)
After examining the works in the watch, Myka points out that it uses black diamonds instead of rubies, which gives Artie an idea. They head to the remains of the Warehouse and Artie brings in the orbiting football … remember that from the first episode? Well, it’s really a scanner that circles 
the world gathering data and dumps it into the Warehouse memory banks on each fly-by. (Actually, Pete’s the one who catches the football and does a Tebow kneel-down afterward.) Artie checks the football’s database and finds “black diamond” has something to do with the Templars; I figured we’d have to run into them sooner or later … it is a secret history-themed show after all. Claudia finds an abbey in Richerenches, France run by the Brotherhood of the Black Diamond. Artie says they’ll have to head over there and tells Leena to get hold of Keeler, the guy who runs the supermarket with the vault in the freezer. Keeler is a historian and Artie needs him and Leena to find an artifact that can destroy Sykes’s bomb so they’ll know what to do if they manage to reverse time.
Claudia says she’s not going; there’s no way to go back far enough to save Steve, so she just wants to use the metronome to bring him back. Pete points out that bringing Steve back to a world without hope isn’t really doing him any favours. Claudia finally agrees to come, but tells Artie that when everything is done, nothing will stop her from doing what she has to do. In France, they find a vineyard called Barbosa and head out there. They’ve started feeling cold, which Artie says is a physical manifestation of
the loss of hope. (Myka: “That explains why Pete didn’t hit on that flight attendant.”; Pete: “I know, that is so not like me.”) They get in touch with Leena and Keener, who say the bomb was created from an artifact fueled by hate, so they need an artifact that represents peace. At the vineyard, Artie and Claudia try to sneak into the cellar while Pete and Myka distract the Brotherhood. Pete’s plan is to start a big brawl, which does distract the Brotherhood goons long enough for Artie and Claudia to get downstairs.
They find a rack of barrels that slides out to reveal a hole in the wall. Artie’s too big to get in—which Claudia points out with several Winnie the Pooh references—so Claudia wriggles inside. She finds an astrolabe that belonged 
to Magellan, but the eyepiece is missing. She crawls back in to look some more and Artie is confronted by a couple of sinister monks (including the leader, Brother Adrian, played by Brent Spiner). Adrian says they have to put the astrolabe back and won’t listen when Artie tries to explain why they need it. Claudia Teslas the other monk and Adrian throws a knife that activates a trap, burying Claudia in the hole. Myka and Pete show up and Tesla Brother Adrian, but Claudia is stuck inside the hole. She says they should go on and find the eyepiece; if they succeed in turning time back, it’ll be like she was never there to begin with.
Artie remembers that Magellan’s captain was named Barbosa and Myka wonders if that means the eyepiece could be in Portugal. Upon looking at the watch again, it now shows the time as 4:18. They call Leena and Keener
to see if those numbers are significant; they go through numerous possibilities (latitude/longitude, dates, years) but can’t come up with anything. Pete mentions military time (16:18), which makes Myka think of Bible verses. Artie figures the “M” on the watch doesn’t stand for Magellan, but for a book of the Bible. Claudia dazzles them with her biblical knowledge … apparently Bible study was big at the institution. Keener finds Matthew 16:18, which is about St. Peter and says the cornerstone of St. Peter’s Basilica in Rome was laid April 18, 1506.
The watch starts counting down again, telling them they have about nine hours to get to Rome, break into the Vatican, and find the eyepiece. They’re reluctant to leave Claudia, but she tells them to get the hell out of there and 
save the world. In Rome, Artie takes them to a restaurant that has a tunnel under it leading straight into St. Peter’s, but the streets are in chaos so the restaurant owner won’t let them in. Myka smashes the window to draw the owners out and starts a fight with the carabinieri to distract everyone. Myka’s arrested, but Artie and Pete get inside and find the tunnel. They find an ancient elevator leading down to the chambers under St. Peter’s, but the power is screwed up. Artie hot wires it and notices the indicator dial inside the elevator is the eyepiece they’re looking for.
Before they can get it, they’re attacked by Brotherhood members. Pete takes them out, but Brother Adrian shows up with a dagger and tackles him. They end up in the elevator and when Artie manages to bring it back, Adrian stumbles out with the dagger in his chest. Pete hands Artie the eyepiece, then keels over, bleeding from a stab wound to his gut. Pete asks if he’ll
remember dying and Artie says no; Pete dies and Artie almost loses it, knowing he will remember. He calls Leena and Keener, who tell him Gandhi’s dhoti might be just what they need since it’s an artifact of pure peace and it was definitely in the Warehouse. Artie assembles the astrolabe, but before he can use it, Brother Adrian revives just enough to gasp out a final warning. He tells Artie if he uses the astrolabe to change time, he can’t tell anyone (because it’ll put them in danger) and he’ll create “an evil of your own making that will follow you for the rest of your days”. Brother Adrian then dies … for real this time, totally, one hundred percent.
Artie uses the astrolabe and time spins backward until he finds himself in the Warehouse just before Sykes’s demise. He’s just freed Myka and Wells 
from their tender trap (the Mary Celeste ropes) and tells them about the bomb in Sykes’s wheelchair. They retrieve the bomb and find Gandhi’s dhoti, but placing it over the bomb doesn’t stop it. Wells and Myka figure that an artifact to counteract hate would have to be used on the source of the hate, Sykes himself. Unfortunately, Sykes is about to be disintegrated when Pete turns the portal off while Sykes is partway through. Myka and Wells wonder how Artie knows all this stuff, but he can’t take the time to explain.
We get a replay of the scuffle outside the portal from last season, but Artie gets there in time to stop Pete from wasting Sykes and tells Pete to get
Sykes back. Pete goes through the portal and pulls Sykes back, giving Myka a chance to toss the dhoti over him. (Artie shuts the portal off … wasn’t Jane still on the other side in Hong Kong? He could’ve let her come back the easy way.) The dhoti removes the seed of evil in Sykes’s soul, which also defuses the bomb. Sykes briefly reverts to his child self and apologizes for all the shit he caused before dying.
Later, Artie argues with Kosan and Mrs. Frederick about allowing Wells to go free again. Of course, Artie can’t tell them the truth, but he knows Wells 
is willing to give her life for the Warehouse, so he insists she be re-instated. Kosan and Mrs. Frederick finally agree, but Mrs. Frederick knows Artie did … something. She has a streak of grey in her hair, so she knows something big happened, but Artie won’t tell her what it was. Artie falls asleep as Brother Adrian’s warning echoes in his ears and he dreams about Claudia stabbing him with a dagger. He wakes up to a call from Leena telling him Claudia is gone … and she took the metronome with her. Season 4 is off to a hell of a start! Come back next week to see what happens with Claudia.