His look of concern is not unjustified. 
Projects that includes libations and hand tools usually don’t end well.
Seems the Big Engineer and the Little Engineer were having some difficulty securing the Tiny Tannenbaum. 

Problem solved. 
And before dinner the tree was trimmed and the halls were decked (with treasures from the Christmas markets.) 

Austrian Christmas tree lights are different than what we’re used to; rather than being a long strand that can be connected to other strands, each strand is an independent circle, meaning a separate outlet is required for each strand placed on the tree, not to mention needing a whole different tree-trimming paradigm.  At first we thought it was a fire safety measure of some sort, but then remembered this is a country that still uses lighted candles on the Christmas tree. No, really.  The candles and the little candle holders that  can be secured to the tree are in practically every store right now. I find this to be a charming tradition, but something tells me that Tony won’t be too keen on setting our tree ablaze with lighted candles on Christmas Eve.