From the Grand Central bombing of Season 1 Episode 1 to Elias' (Rick Cosnett) suicide in Season 1 Episode 11, "Quantico" has managed to keep fans right at the edge of their seats. We are almost 100% sure Alex (Priyanka Chopra) is not a terrorist, and so are her friends at the FBI, but the world is still unaware of the true nature of the bombings.
Up until the mid-season finale episode "Inside", Liam (Josh Hopkins) and Miranda's (Aunjanue Ellis) plan was to keep holding Alex in the FBI command centre in the hopes of misdirecting the real bombers. However, the real bomber may be too close to the operation and actually blindsiding Liam and Alex, while carrying on with their operations.
As of "Inside", we know Elias had some sort of association with the terrorists and tried to pin the bombings on Simon (Tate Ellington) who, if we are honest, did have a shady past. However, Simon clarified although he did make the blueprint for the bombing, he left a deliberate flaw in the plan, which the actual terrorist must have fixed after stealing it.
In "Inside", Alex was literally a couple of hours away from being sentenced for the supposed crimes she committed, but the next explosion, at the command central, changed everything. The bomb went off when she was in FBI custody, meaning there was at least another bomber, and he or she was still out there.
Liam and Miranda can even come clean about holding Alex on purpose, for the benefit of the case. We do know someone important to the NATs, especially Alex, has been killed in the second bombing, and once we know who that is, it will be easier to assess how the story will proceed.
Meanwhile, the presence of a new character, Caleb's lookalike Mark Raymond (Graham Rogers), has also added more drama to the mix. Most fans believe this Mark Raymond character could be the actual bomber, or at least have some connection to the bombers, while many also believe we are not actually done with Shelby's sister. That she may return as the terrorist is a common theory.