In the last episode of The Flash, we saw what really happened to Harrison Wells and how he became the person we saw in the last 16 episodes. And the truth is, the person we saw wasn't the real Harrison Wells because Harrison Wells was already dead or gone 15 years prior. Eobard Thawne lost his super speed after supposedly killing Barry's mother. Now he was stuck in the past with no way home, so he started planning his return and the first step, was to get Harrison Wells.
He then went on to engineer the car crash that would eventually kill Tess Morgan, Harrison Well's wife. In Harrison Wells' moment of weakness, Eobard connected him to a device from the future that changed Eobard's appearance and cell structure, to be like Wells'. That explains how the blood at Nora Allen's death didn't result in a match. This resulted in the real Harrison's body becoming mummified.
I feel like the body found in the ground by Detective West and Detective Lance is either the body of Harrison Wells or Mason. Seeing as how Eobard wants to go home, he needs Barry's speed. So he took Harrison's identity and created the Particle Accelerator, to ensure that Barry got his super speed quickly. Eobard revealed that the Particle Accelerator was originally created by Harrison Wells and Tess Morgan in 2020, and we assume that gave Barry his powers. Eobard sped up the process, because he was trapped in the past.
I feel these flashbacks now give an indication of what Eobard has planned for Barry and what his endgame is. My theory is that he wants to use the device, that he used on Harrison Wells, on Barry and get Barry's speed. This will allow him to return home and kill Barry at the same time.
With 6 episodes, who knows what other interesting and jaw dropping moments will happen on [The Flash](series:1068303).