This time the year in focus is 1939 and the signing of the notorious Molotov-Ribbentrop Pact (sometimes also called the Hitler-Stalin Pact) between Nazi Germany and the Soviet Union. It marked the death-knell for independent Latvia and indeed many other independent states in Europe.
The documentary covers ground is often ignored in other histories of the time, namely, the period between the signing of the pact and the formal disappearance of sovereignty when Latvia remained nominally independent but was forced to accept the presence of large-scale Soviet forces on its territory.
It is a fascinating tale, depicting actions by the Latvian government that seem to have stemmed from both a naive belief that it was possible to trust Stalin and, more probably, desperation at finding themselves hopelessly outnumbered and surrounded on all sides by the Red Army.
There is a particularly thought-provoking comparison with events in Finland, which at the time was considered the fourth 'Baltic state' alongside Latvia, Lithuania and Estonia, and which courageously maintained its independence, albeit at a heavy price.
According to LTV "The Keys" series tells of the most important or "key" events, personalities and turning points in the history of the Latvian state from 1918 to the present. The purpose is to reveal each selected event from an unusual point of view, as if "unlocking the door" to lesser known and therefore particularly intriguing facts.
"Such an exploratory approach, bypassing the usual stereotypes of presenting history, will allow viewers to perceive what is known to others and to better understand what has happened in the context of today's experience," says LTV.
The show is made by VFS Films, a long-time partner of Latvian Television and it is hosted by Mārtiņš Ķibilds, a distinguished cultural journalist who sadly passed away late last year.