But by the time the FBI's fake car bomb was parked outside the Cactus Bar & Grill in Chicago on Friday night, only Adel Daoud, 18, was there to push the button on what he thought was a detonator. Only Daoud was under arrest.
So what happened to the second person, an unidentified male who Dauod referred to as his "sahaba," an Arabic term meaning companion?
Federal court records reveal a leader at a local mosque played a vital role in convincing the second man to abandon his plans for jihad just weeks before the would-be attack.
Undercover FBI agents, meanwhile, continued to lean heavily on Daoud. The agents supplied him with almost everything he needed to plan the attack and told him they were relaying messages from a foreign sheik who wanted to know if he was truly prepared to carry it out.
The documents allege Dauod's friend, listed only as "Individual C," was closely involved in the plan for months. Daoud had allegedly originally considered targeting military recruiting centers, malls and tourist attractions until the friend came up with a "really good plan" for attacking a concert. They eventually scuttled that idea, however, and settled on the bar.
At some point, though, the documents show Daoud's friend became nervous. He thought the undercover FBI agent was a spy. But the agent tried to reassure them, telling Daoud "anybody who spies must be killed."
While the friend seemed have some reservations, it wasn't until both he and Daoud were yelled at by a local sheik, who had heard them discussing jihad, that he reportedly decided he wanted out. The documents don't name the sheik or say which mosque he was from.
On Aug. 18, the affidavit says, Daoud talked to the undercover FBI agent, who "explained that, as a result of this intervention, Individual C no longer wanted to be involved in the attack because he had reservations about killing 'random americans,' as opposed to those involved with the United States military."
Daoud's father also told him to stop talking about jihad, according to the affidavit. But the interventions didn't dissuade the teen. He allegedly went ahead with the plan after a conversation with an undercover FBI agent, who said the a foreign sheik "wanted to make sure this is something that is in your heart."
"He wants to make sure you have no doubt in your heart," the agent said, according to the affidavit.
Daoud replied that there was "sufficient proof that this in my heart."
On Monday, Dauod's attorney said the FBI had guided his client the whole way, from when he was 17.
"The way the government thinks is if they find somebody on the Internet that might be talking about radical Islamic beliefs, what they do then is they have to make sure he is not going to commit terrorism, so they invite him along," defense attorney Thomas Anthony Durkin said, according to the Chicago Tribune. "I guess we have to wait and see whether or not he is going to blow up this fake bomb they have created for him. I find that somewhat suspicious."