Preheat oven to 400 degrees F (200 degrees C). Roll out half the pastry and line a 9-inch pie pan; trim crust to the rim of the pan. Loosely cover with plastic wrap and refrigerate.
Combine sugar, tapioca, and cinnamon. Toss sugar mixture with blueberries in a mixing bowl and sprinkle with lemon juice. Let stand fifteen minutes. Meanwhile, roll out the top crust into a 10-inch circle. Cut into half-inch strips. Pour blueberry mixture into chilled pie shell and dot with butter. Add the pastry strips one at a time, weaving a lattice. Flute edges.
Place pie on a baking sheet to catch drips. Bake in the preheated oven for 40 to 50 minutes, until filling is bubbly and crust is light brown. Cool completely before serving.