The next morning, Sarah wakes up, feeling better. "We need to go," says Cameron, and when Sarah asks, "Where?" Cameron merely says, "I'll show you."
The trio stroll into a bank, where Cameron says she has a "safety deposit box." When did she get it? "1963," says Cameron, without any further explanation, as the three of them pass the bank's cornerstone, upon which a plaque announces the stone was laid in 1963. Banking etiquette must have been different back then, because inside, Cameron grabs the gun of the elderly security guard and yells for everyone to get down on the floor; one of the tellers pushes the silent alarm button, as Cameron orders another one to give her the keys to the safety deposit boxes and cocks the gun to show she's serious. Sarah looks unsure, but has probably realized that asking Cameron anything is only going to produce one of her vague non-answers.
Downstairs, Cameron orders the teller to lock them into the room with the safe-deposit boxes and to move away from the door ("I'll know if you don't," she says, with just a hint of threat). Thusly locked in, Cameron punches in one of the boxes and produces a few key rings from inside it, and tosses a couple to Sarah and John, telling them to use the keys to open the corresponding boxes and put everything they find on the table. "Carefully," she stresses, and John hops to instantly, while Sarah moves a little more slowly, but picks up speed when she recognizes they're assembling some kind of weapon.
Outside, the entire Los Angeles Police Department is mobilizing around the bank. Over in the FBI offices, a colleague flags Agent Ellison down to check out the security feed from the bank robbery. "Don't you know 'em?" asks the other agent. "Less and less all the time," he says. Given that there was a student who was shot several times, whose body disappeared and who is now holding up a bank with two other fugitives, I think his bafflement is entirely understandable.
John asks if the weapon pieces are from the future, and Cameron reminds him that you can't transport anything non-living through time. "You sent someone back to build it," she says, and John looks impressed with himself. Given that Bill and Ted, during the course of their excellent adventure, managed to come up with the idea of sending stuff back in time at convenient moments, he needn't be too smug.