“You just knew what things meant.” And Sandy, surprised, and a bit suspicious, does not disappoint. “You were really good at sounding like you knew what a line of poetry meant,” Martina says. Smith, demanding in the engagement it requires, and rewarding of that engagement, as one picks away at the words she has used to build it. You could never tell by looking at it that it’s even a lock, or that it has any mechanism at all inside it, never mind find how or where the key goes into it to open it.” Which is, of course, a fine description of this novel, itself a lock, crafted by a smith, that is, by A. “It’s really beautiful,” Martina tells Sandy. Martina was held and questioned while transporting the centuries-old Boothby Lock for the museum where she works. In a pandemic-ravaged and post-Brexit Britain, our narrator, Sandy Gray, who is anything but gray, character-wise, though in her present state of personal and political despondency she might well feel she is, receives an unexpected call from one Martina Pelf, formerly Martina Inglis, a university acquaintance who has recently been held for seven and a half hours at border control, an officer annoyed by her dual citizenship (“Is one country not enough for you?”), and Martina is calling to share this with Sandy, and to ask Sandy a question - and so begins Ali Smith’s 18th book, the superb novel “Companion Piece.”