This unadvertised sale is back on again! Similar to a sale that we posted a few weeks back, it looks like Delta and SkyTeam partners are undercutting United hubs in the US to StarAlliance destinations in Europe. These amazing fares can be had beginning at $436-8 to Brussels & Zurich, and $504-6 to Frankfurt & Vienna.
Since it is unadvertised it may not last very long. Book quickly if something catches your eye. Most third-party booking sites have a 24-hour free cancellation policy so you'll have a day to figure out the details.
Travel is available on a wide range of dates, but generally through mid-May and from mid-August through October. Travel Monday through Thursday, with the occasional Sunday departure available, 21-day advance purchase and a 7-night minimum stay is required. Most of these are main cabin fares, which means your first checked bag will be included as well. Click on the fare details for more booking information.