Run into someone or something: meet someone or something unexpectedly
偶然に（人・物に）出会う

Sam: How's it going?

Tim: I ran into your old coworker the other day. His name is Roger, isn't it.

Sam: Yeah, that's him. What's he been up to these days?

サム：最近どう？
ティム：先日、君の古い同僚に偶然出会ったんだ。彼の名前はロージャーだったね
サム：うん、彼だよ。最近彼はどうしているんだろう？