Ah, the Victoria Line and the whole King’s Cross St. Pancras setup can be a bit confusing at first, so you’re not alone!
First off, let’s tackle the Victoria Line bit. King’s Cross St. Pancras is a massive station, but the Victoria Line is definitely in there. When you’re at King’s Cross St. Pancras, just follow the signs that say “Victoria Line” (they’ll have a light blue line on them). You won’t need to leave the station or anything like that—it’s all connected underground.
Now, about King’s Cross and St. Pancras—this is where it gets a bit interesting. They’re technically two different stations but are treated as one because they’re connected. King’s Cross is where you’ll find the National Rail services and some Underground lines, while St. Pancras is home to the Eurostar and other National Rail services. But since they’re joined at the hip (so to speak), you can walk between them without having to go outside or even touch out with your Oyster or contactless card if you’re just changing Underground lines.
So, no worries—there’s no need to transfer between stations as such. Just follow the signs, and you’ll be on the Victoria Line in no time!