This YA series about Norby, the Mixed-Up Robot, was one of my favorite reads as a child, not to mention my introduction to Isaac Asimov (even if Janet actually did do all the writing). Occasionally, I come upon paperback versions in used bookstores that collect two of them together, and I snatch them up instantly. This one collects Norby and the Queen's Necklace (what I remembered as my favorite) and Norby Finds a Villain. It's excellent YA literature, with a decent breadth of imagination on display in just these two stories. Jeff and Norby and a variety of other characters find themselves in the near future, pre-Revolutionary France, Roman times, prehistoric times, far-future utopias, far-future dystopias, hyperspace, aberrant future versions of Mars, and dangerous alternate realities just within the confines of these two short tales! Norby himself is as fun as ever, and the supporting cast doesn't disappoint. The Queen's Necklace isn't quite as good as I remember (not all of the temporal shenanigans actually work out in the end), but it's solid fun, as is Finds a Villain. (originally written December 2007)