Hi there!
The answer is: "it [Stalin's five year plan] was a plan that led to the deaths of thousands".
In 1928 Joseph Stalin launched the first Five Year plan. This plan was a list of economic goals for the Sovjet-Union based on the idea of communism. An important part of this plan was the collectivisation of agricultural lands. Farmers weren't pleased with these plans and soon after the first implementation of the plans, they failed: Stalin wasn't able to produce enough food, which eventually caused many people's deaths in the Sovjet-Union.