Quite what form that will take remains to be seen at 6 p.m. but you can get a taste in the video below, made by the Scandiweb group who will be charge of proceedings.
According to Riga City Council the chain reaction will be so long it will get into the Guinness Book of Records with an official from the compiler of big, small, long, short, high, low etc things on hand to officiate.
"On 2 December planned to beat the record (currently held by Hungary with 383 steps) with a 400 step long machine, which will culminate in the Town Hall Square spruce lighting up," Riga city council promises.
About half past 6 p.m. the Rīga Christmas tree was successfully lit via the contraption featuring levers, balls, a fan, several wheels and buckets, and even a coffee maker.
"It's the first time I've been so worried," said Riga mayor Nils Ušakovs, who with a Scandiweb representative launched the chain by pressing a classy red button.
The remaining sequence of events was initiated by a sound meter triggered through the screams of hundreds attending.
The chain was in part located inside the City Hall and its progress was screened on a monitor for about ten nerve-wrecking minutes as the chain made its way from the second story to the ground floor and outside.
A broom-equipped snowman made the final touch, and for all intents and purposes the event seemed a success - and LETA reported later on December 2 that, indeed, Riga is now the record holder for the longest Rube Goldberg chain with 412 links, according to Guiness World Records representative Seida Tsubaki-Gemiki.
You can read more about Riga, the home of the Christmas tree in a feature we produced last year HERE.