At 65 pc, MBM-12 is the nearest known molecular cloud.  Located
 far from sources of FUV radiation, it provides an ideal laboratory
 to study translucent interstellar gas.  MBM-12 has been extensively
 mapped in (13)CO(1->0) and 14 molecular cores have been identified
 in the complex.  Deduced molecular hydrogen densities range from
 10E+3 to 10E+4 cm-3 and excitation temperatures are about 10 K.
 MBM-12 is thus a translucent cloud:  densities and temperatures
 for the cores are typical of dark clouds, while visual extinctions
 (Av is about 2 mag) are typical of diffuse clouds.  Because of the
 former property, molecules are able to form in abundance in
 translucent clouds.  However, since Av is low, the ambient radiation
 field plays an important role in their chemistry.  MBM-12 cores have
 visual extinctions such that H2 -> HI and CII -> C -> CO
 photochemistry is occuring.  For MBM-12 most of these species have
 either already been studied or are currently being investigated.
 Missing from, and vital to, any complete characterization of the
 physical state of the atomic and molecular interstellar medium
 of the MBM-12 complex is any direct measurement of ionized carbon.
 ISO LWS observations of [CII] will be used in conjunction with
 existing [CI], CO, and HI data to study the properties of the 14
 atomic/molecular cores in the MBM-12 complex.  ISO measurements of
 [CII] emission from MBM-12 can provide important constraints on
 models for photodissociation regions (PDRs) in translucent clouds
 near weak FUV radiation fields.