Here is an hypothetical scenario where the Soviets annexed the Baltics late 1939 on the eve of the Winter War. They used these bases to springboard into Southern Finland while commencing an attack on the front. The Finns have lost their beautiful capital, but much to the Soviet's disappointment, this won't break the Finnish spirit just yet.
In the early hours of November 30th 1939 , the Soviet Kirov cruiser and a few accompanying destroyers are sighted off the coast of Hanko. The coastal guns line their guns ready to fire, but just then are hundreds of Soviet planes seen in the sky, with parachutes falling over Finland. Before the coastal soldiers regain their thought, the Kirov has already fired - knowing where the coastal artillery positions are. The invasion of Finland has begun.
The Soviets have rammed their way into Helsinki in a very ambitious naval operation. Due to the inexperience of amphibious operations and brave Finnish garrisons in the city, the Soviets take immense casualties, but they still manage to take the city. The Finns know they cannot hold, as they plan a counter-attack code-named Väinämöinen. With foreign volunteers and the 6. Divisioona on the way to Helsinki, it is a race against the clock to take the city without losing desperately needed men for the front.
Delay the Soviets around Hanko and Turku as best as you can, Turku serves as a base for foreign reinforcements - if you think they'll be necessary.
Hold the Mannerheim line as historically as possible, or move divisions inland to sweep out scattered soviet parachutists. Heavy soviet reinforcements will arrive in December making your positions untenable if you cannot clear inner Finland.
This is a relatively easy scenario, I wanted to make something rather unique and interesting in the Black Tide expansion while being relatively reasonable as possible.
Good luck and have fun, any problems let me know and I will try to correct or balance upon request.
Changed starting date and tried to fix some errors!
Updated some balance and objective issues - Soviets are stronger and more aggressive! This is a fight to the death!
Swedish Tank Brigade (PB) removed.