context: Michael Faraday (Jeff Bridges) is a college history professor at George Washington University who has been raising his nine-year-old son, Grant (Spencer Treat Clark), since the death of his FBI agent wife, who was killed in the line of duty in a scene loosely based on the real-life Ruby Ridge incident. Somewhat of a specialist regarding American terrorism and due to teach a class on terrorism at the university, Michael starts to become suspicious of his new suburban neighbors, Oliver (Tim Robbins) and Cheryl Lang (Joan Cusack), whom he's just met after taking their son, Brady (Mason Gamble), to the emergency room following a reported fireworks accident.At first his suspicions are based on little things such as Oliver's architectural blueprints that seem to be for something other than the shopping mall he claims he's building, as well as pieces of mail that contradict where Oliver said he attended college. Neither his girlfriend and former student, Brooke Wolfe (Hope Davis), nor his wife's former FBI partner, Whit Carver (Robert Gossett), believe any of his wild theories.After doing some digging, Michael discovers that Oliver's real name is William Fenimore, and that he built a pipe bomb and used it to try to blow up a postal office in Kansas when he was 16. William/Oliver confronts Michael over his looking into William's past. He reveals that 'Oliver Lang' is the name of his friend, who died in a hunting accident. William's family had owned a farm but it went broke because the government 'appropriated' the river that ran through it 'for other uses'. As a result the crops died and they could not raise any animals. William's dad then killed himself and made it look like a tractor accident so the family could claim the life insurance. He left a note for William explaining everything. He built the pipe bomb to get back at the government. When William's friend Oliver died he took his name the next day to hide his past. This makes Michael think twice about what he had found out.Michael continues to uncover what could be possible evidence and becomes even more wary of Oliver and Cheryl. Michael's girlfriend, Brooke, casually spots Oliver and follows his car after witnessing a suspicious package delivery in a garage. Her trail ends up in the headquarters of a mail delivery company from where she decides to call Michael and leave a message, finally accepting his fears as founded; unfortunately, after hanging up, she turns around and stumbles on Cheryl, who had obviously heard the whole message.Brooke's murder (which happens off-screen) is covered up by making it look like Brooke died in a car crash. Michael realizes this after finding out, a few days later, that at least two voice messages were left in his answering machine and then erased by someone else (how is never explained). He tells Carver that Lang may have been involved in her death, and is going to get proof by traveling to St. Louis to talk to a terrorist's father, Arthur Scobee. Scobee's son blew up an IRS building five years ago (a thinly veiled version of the Oklahoma City bombing), killing himself and eight children in the process. It becomes obvious that Scobee was set up. Another clue leads Faraday to suspect that his son may be in danger when he talks with Scobee's distraught father and learns that Scobee was involved in a Boy Scouts-style organization and that he knew the head taskmaster... a person that Oliver also knows.Eventually the conspirators use a field trip with a Scouts-style organization to keep Faraday's son Grant as an unknowing hostage. Faraday confronts Oliver while he is throwing a party, where Oliver finally reveals that he indeed is a terrorist and is plotting something big within a few days and orders him to keep quiet about what he and his group are plotting to do.Growing more desperate, Faraday learns about the origins of two phone calls made to his house that were erased; one being from Carver and the other from Brooke which was made from a payphone at a local shopping center. Faraday rents a car the next day and after sneaking out of his house, goes looking for leads when he spots a van that his son is in. While following the van, Oliver Lang appears and rams into Faraday's car and begins to beat him up. After getting into a fistfight with Oliver in an old building, Faraday bests him and tries to help him understand that killing hundreds of people won't make a difference. When Oliver refuses to call off the bomb and lets it slip that the van is on their way to the FBI building, the frantic Faraday has to stop it before it's too late.In a harrowing chase sequence, Faraday, in a clear panic, drives through the crowded streets of Washington DC and forces his car into the secure parking garage of the FBI federal building, only to discover that he has followed the wrong van into the parking garage. Attempting to calm Faraday, Whit Carver informs him that he is the only person not cleared to be in the garage. Realizing his mistake too late, Faraday rushes to the trunk of his rental car, opening it to reveal.... a hidden bomb just seconds before it explodes, killing Faraday, Whit, and 182 others.Posthumously, Faraday is vilified as a terrorist who destroyed the FBI headquarters under the motive of seeking revenge for his wife's death. The Langs and their conspirators (some of whom include the Scout taskmaster, a telephone maintenance man, and at least one of Faraday's students) completely get away with it. Grant, now orphaned, ends up living with relatives, not knowing of his father's innocence. After the Langs decide to move out of the neighborhood, Cheryl suggests to Oliver that they should go "someplace nice, someplace safe"... strongly implying that sooner or later they will strike another government target elsewhere, as well as find another fall guy to take the blame for their evil actions as they did with Arthur Scobee, and Michael Faraday... whom was just their latest victim among so many.
question: Who is unaware of his father's innocence?
answer: Grant