Early in Nature Cure Richard Mabey returns continually to the swift, who in its spectacular migration may not touch down for well over a year. In Ted Hughes's phrase, the reappearance of the swifts tells us that "the globe's still working." When we encounter the author in the opening pages of this powerful memoir, his corner of the globe is decidedly not working. A deep depression has left him alienated from his work and his family, financially...