Short answers, pulled from the story.
The Lapland War was an armed conflict between Finland and Nazi Germany fought primarily from September to November 1944 in Finland's northernmost region, Lapland. It arose after the Moscow Armistice of the 19th of September 1944 required Finland to expel or disarm all German troops on its soil. The last German soldiers left Finland on the 27th of April 1945.
Finland had been a co-belligerent with Germany against the Soviet Union since 1941, but signed the Moscow Armistice with the Allies in September 1944. The armistice required Finland to expel or intern all German troops remaining on Finnish soil. Soviet pressure to enforce these terms forced Finland to escalate from a tacit withdrawal arrangement to open hostilities on the 28th of September 1944.
Operation Birke was the German 20th Mountain Army's planned organised withdrawal from Finland northward into Norway, formally designated on the 9th of April 1944. It involved evacuating over 200,000 soldiers, 32,000 horses and mules, and between 17,500 and 26,000 motorised vehicles, along with 180,000 tonnes of supplies. It was later superseded by the more rapid Operation Nordlicht, approved by Hitler on the 4th of October 1944.
German scorched-earth tactics destroyed an estimated 14,900 buildings representing 40 to 46 percent of Lapland's total property, 470 kilometres of railway, 9,500 kilometres of road, 675 bridges, and 3,700 kilometres of telephone and telegram lines. Reconstruction lasted into the early 1950s, and the railway network was not fully functional again until 1957. By 1973, demining teams had recovered more than 1,142,000 explosive items from the region.
Finnish casualties totalled 774 killed, 262 missing, and around 2,904 wounded. Germany suffered around 1,000 deaths and 2,000 wounded, with 1,300 soldiers taken prisoner and handed over to the Soviet Union under the terms of the Moscow Armistice. Each side sustained around 4,000 total casualties.
The Battle of Tornio was an amphibious Finnish operation that began on the 30th of September 1944, when three transport ships departed Oulu without air or naval escorts and landed troops at Tornio on the 1st of October. Around 12,500 Finnish soldiers came ashore across six landing waves. German aircraft sank two Finnish ships, the SS Bore IX and the SS Maininki, on the 4th of October. The Germans withdrew from Tornio on the 8th of October after a week of counterattacks.