This was a fantastic, action-packed episode that delivered everything we needed to move the main season arc along and fill in some details on key character backgrounds.
We had Coulson and half his team heading off on The Bus to track down the mysterious city discovered at the end of the last episode, the other half of the team digging into the background of Big Bad Whitehall (Reed Diamond) - with help of some old Strategic Scientific Reserve (S.S.R., the precursor to S.H.I.E.L.D.) files (and flashbacks to 1945 involving Agent Carter), and the errant Agent Ward kidnapping his brother the Senator for some intimate family time.
During all this we learned the (possible) history of The Obelisk from Skye's father, the brilliantly awkward Doctor (Kyle MacLachlan), its apocalyptic connection to a race of blue aliens that came to Earth thousands of years ago (just say Kree, people, put us all out of our misery) and certain people (can we say Inhumans?) who can safely use the artifact, including the exotically beautiful Dichen Lachman (a Whedonverse stalwart).
After 44 years in a S.H.I.E.L.D. prison, aged Nazi scientist Werner Reinhardt was released by Alexander Pierce (see Captain America; The Winter Solider) only to discover that Dichen's character hadn't aged at all and so he drained her (as mad scientists do) to create a restorative that made him a young man again. He then adopted the identity of Whitehall.
In a story pulsating with comic book lore, The Things We Bury did a magnificent job of setting both sides of the conflict - S.H.I.E.L.D. and Hydra - up for discovering the lost city, which I guess is where we'll all be going next week.