Eighteen years after 9/11, what's going on in Guantanamo?

What's often referred to as the biggest criminal trial in US history has met with a host of obstacles, some logistical, others stemming from the central issue of the torture the detainees endured while held at now-infamous CIA black sites. Much of the information sought by defence legal teams is classified for reasons of national security - but the US government still hasn't provided a clear guide to exactly what is and isn't classified.