Paris - a shaky start

We decided to have the obligatory weekend in Paree. Eurostar train, of course: gets there fast and to a central station (Gare du Nord). So we book and start off.
Eurostar leaves from Waterloo, and it was nearly ours. Normally, to get there from Victoria, one would take the eastbound District or Circle tube, then change to a southbound Jubilee/Bakerloo/Northern (all go to Waterloo). So unaccountably, I (W) first choose a westbound platform.... Not a good start. Which I compound by losing M while crossing against the flow of Friday commuters to the Eastbound platform. We eventually arrive at Waterloo (all of 3 km away) somewhat frazzled.
Eurostar itself is a very fast train - well over 150mph at peak. Doesn't really feel like it at night, when we leave. We have to stop (that's zero mph...) for 'permission to enter' the Channel Tunnel. So that blows the 100+mph average. And it's dark, a characteristic of night everywhere it seems, so the only thing we observe about France after we exit the Channel Tunnel is that they have orange street lights and neon signs, too. Not very exotic.
Then, the train is ordered to 'come to an immediate halt' somehwere north of Paris, at some sad looking wayside station. This in itself is never a good sign, and is confirmed when the local losers start throwing whatever's handy - bricks, bottles - at the train! We exit south at some speed.
We arrive in Paris without further ado, and find our hotel, down Rue Magenta then up a typically quaint and tiny street (Rue Luciens Sampaix).