One Hundred Twenty-One Days by Michèle Audin   {Reviewed by THOMAS} In mathematics a problem may be solved if all the terms can be assembled on one side of the equals sign and the equation solved for zero. In history, unfortunately (or, in the minority (but probably more useful) view, fortunately), the practitioner is beset with a range of imprecise difficulties unavailable to the mathematician: the problem to be solved becomes more entangled with other problems the more it is pursued, the terms can never be completely assembled and are often vague, lost or conflicting, and it inevitably proves impossible to assemble everything (literally everything) on one side of an equals sign, leaving nothing on the other (to say nothing of the problem of the location and role of the historian (the term used here in its broadest sense) in historical enquiry). Much insight and understanding can be achieved, though, from the application of mathematical disciplines to historical problems, and by the testing, exchange and  manipulation of terms through inverse (and thus intimately related) functions (addition/subtraction, multiplication/division). Michele Audin is a fairly famous mathematician and a member of OuLiPo (a group dedicated to extracting new potentialities from literature largely by the application of mechanisms and constraints). This novel is clustered around a number of mathematicians working in France before, during and after World War Two, and the black hole around which its calculations spiral is the transport and annihilation of French Jews during the Nazi occupation and the extent of French complicity and collaboration in those events (still very much an unhealed wound). The mathematicians are, variously, Jewish, French, immigrant, German; lauded, suppressed, collaborator, disguised, hidden, incarcerated in a mental hospital. The novel asks, is there an ethical dimension to mathematics? What is the relationship between mathematics and life? Is there such a thing as Jewish/German/French mathematics? Each section of the novel is told in a different way: letters, diaries, descriptions of photographs, newspaper articles, psychiatric reports, indices of archives, travel notes and lists of numbers and their significance. Each mode is a historical residue with its own texture, the kind of range of differing information from which ‘history’ is assembled, but each mode is primarily the vector of its blind spot, that which is not revealed, the information that cannot be said. It is perhaps these blind spots that must be solved for the zero which is the annihilation of French Jews and the anti-Semitism which has beset France before, during and after that time.