First appearance of KC, Alice, and The Guardian since Series 3.
KC, Alice, and The Guardian appearing again could have been a tease of what might of happened in Series 6. The guards in the scene could've belonged to what may have been the villians in Series 6. A similar occurance happened in Series 3. The Technos were teased all throught the finale of Series 3, before they're introduction at the end of the episode.