His best-known work is The Frozen Book (Jäine raamat), about a Soviet expedition to Antarctica.

In 1949, he participated in the Soviet repression campaign of deporting Estonians into eastern parts of Russia.

In February 1972, a bas-relief of Smuul created by the sculptor Matti Varik [et] and the architect Allan Murdmaa was unveiled on the wall of the Writers' House in Tallinn's Old Town.

Instead, in 2024, the Writers' Union decided to install a plaque below the bust with a QR code explaining Smuul's complicity.

Before his death, he lived for three or four years with the radio and Finnish-language television editor Ellen Noot.