The Year of the Slow Invasion

The Year of the Slow Invasion, (PROSE: The Whoniverse) also known as the Cube Invasion, (PROSE: The Secret Lives of Monsters) was a gradual invasion of Earth over the course of 2012 and 2013 (PROSE: The Whoniverse) by Shakri cubes so that the Shakri could eliminate humanity.

Believing humanity to be a plague that would bring ruin to the universe should they begin colonising the stars, the Shakri decided to conduct "pest control" by sending their cubes to infiltrate 21st century Earth in the month of July. They were inactive but still were believed to be a threat. The Eleventh Doctor, Kate Stewart, and Brian Williams decided to watch the cubes until some kind of activity occurred, though the Doctor eventually got bored and didn't resume observing the cubes until he returned to Earth in June. The cubes were subjected to numerous tests by UNIT to see what could destroy them; through human methods, it was impossible. Eventually, the Shakri began using an android to command fake orderlies, which kidnapped multiple humans over the course of the year.

The following July, every last cube performed some random function; some of them were harmful (such as spewing fire and causing mood swings) and some were just plain annoying (like playing the "Chicken Dance"). The cubes then sucked in electricity, using it to stop the hearts of one-third of the human population. The Doctor infiltrated the Shakri ship and used the cubes' programming to restart the hearts they previously stopped. The ricocheting wave of energy caused one of their ships to explode, sealing them back outside the universe. (TV: The Power of Three) The general public came to believe the Cube Invasion had merely been an advertising campaign that "got out of hand". (PROSE: The Secret Lives of Monsters)

Behind the scenes

 * The Whoniverse placed the Year of the Slow Invasion shortly after the start of the 2012 Olympics. Meanwhile, the time elapsed as described by the Ponds in The Doctor, the Widow and the Wardrobe, Pond Life, Dinosaurs on a Spaceship, and The Power of Three would suggest a 2015-2016 placing at earliest. Additionally, Rory's age of 31 described in Dinosaurs on a Spaceship coupled with his birthyear (implied to be in Let's Kill Hitler and confirmed to be in The Broken Man) of 1989 would suggest the starting year as 2019 or 2020, assuming he isn't factoring in any time spent in the TARDIS while talking to Brian.