"Tomorrow" picks up right where we left off, with Cole staggering through disease-ridden Chechnya in 2017.
He hears a familiar voice and listens to Cassie send out a plea to the immune. Their antibodies may be the key to a potential vaccine after all.
In 2043, Jones explains that since the virus keeps mutating, it's impossible Foster found a cure. The only option is to stop the plague in the past, and for that to happen they must take Foster's Core by force.
Knowing an attack is imminent, Ramse returns to Spearhead and asks Elena to trust him. Foster lied about a cure he tells her, but she assures him the cure works; she witnessed it first hand. Foster discovers them snooping through files and holds them hostage.
Meanwhile, Whitley pleads with his father, explaining that Foster has been lying all these years. Jones has a real solution.
It's not long before Jones arrives at Spearhead and makes it very clear she will be leaving with the Core. Foster can give it to her willingly, or she will take it by force.
This leads to a quick flashback to 2041, Ramse and Cole are starving when they come across a group of people that killed a deer. One of the men turns out to be Whitley, and he takes the scavs back to the Temporal Facility. Jones interrupts their torture session when she hears Cole's name. She tells him she's been waiting for him.
Back in the past, Cole is caught in a riot but manages to convince the American soldiers he's immune. When they spot the VII mark on his arm, he's loaded into a car with an American military woman. She does not provide much information, but is prepared to return him to the U.S.
Upon arriving in the states, Cole finds himself at another riot scene; this one outside the CDC in Baltimore. Jennifer Goines is there speaking to a group of young women. "We daughters shall make from twelve what man could not. Yes, an army" she tells them.
Inside the CDC building Cole is reunited with Cassie. Though she is pleased to see him, she appears weak and sick.
Cassie tells Cole they've been through a lot together the past two years. Of course, he hasn't lived through it yet so her words remain a mystery. What is clear, is as expected, she failed to find a cure and is dying herself.
She asks Cole if he found the red forest, but remembers she can't say any more or risk altering the path he's on. She does, however, give him a piece of paper with an address on it telling him his life depends on it.
In 2043, Jones and Foster chat about their first year underground and sneaking upstairs to look at the stars. The two begin to quote Shakespeare and talk of better times. Suddenly, Jones pulls a gun on Foster and kills him. The Spearhead attack begins in full force, with Whitley's father switching sides. The Project Splinter team shoots their way to where the Core is housed. There are many casualties, including Whitley dad and one of Jones' scientists named Lasky.
Once the new Core is installed, Jones splinters Cole home and we see the scratch on Cassie's watch heal itself. What does this mean?
Though Jones told everyone the virus could not be cured, she burns a piece of evidence proving the cure was indeed successful. Ramse defended Jones' actions, but Elena asks him if it's possible Jones lied. Wouldn't she also do anything for her mission?
A quick flashback to 2041 show us Cole had no interest in Project Splinter, it was Ramse who forced his hand. Ironically, it's now Ramse that tells Cole this mission has to stop. Jones killed all those people at Spearhead, yet Foster's cure was real. If Cole continues with his mission, Ramse's new family will be erased. Cole tells his friend his son's already dead, not cool.
The BFF's now find themselves on opposite sides of the argument. How far will Ramse go to protect his family? How will Cole deal with it?