Double Jeopardy by Ferret

Apart from 1 and 13 Across which are normal, every clue is really two clues, separated by an extra word, leading to two symmetrically placed answers; either answer may be clued first. In clue order, the initial letters of extra words provide a hint to the theme.
One jeopardy (8 contiguous cells along an appropriate path) must be moved thematically towards the other (6 cells in a line), leaving empty cells, replacing the contents of others and, ignoring spaces, always forming real words. Solvers must highlight the full name of the theme’s author (a total of thirteen cells).
    1    Fourth dimension personified in mysterious hermit surrounded by death (10, 2 words)
    9/10    Motions withdrawn in Holyrood to join vote advanced by Member pursuing money for local mother (3,3)
    12/14    Châteaux bottling water in France impeded right to enter local river for a long time (3,3)
    13    Demonstration that drops brass bobs finally for Foucault maybe (4)
    15/16    Nick in Leith made up a story about neo-Nazi trouble following nationalist’s arrest (4,4)
    17/19    Mathematician’s led around after work catching wild time in Florida (5,5)
    22/23    Mark leaves in scuffle erupting regularly in Muslim city (3,3)
    26/27    Notice electron repelled by ruthenium in sort of dance; negative particle almost lost circling lutetium (5,5)
    28/30    Country after independence followed temptation to abandon flag (4,4)
    31/32    In the line of symmetry, grout holds square lintel bearing stone returns in highlander’s quarters (5,5)
    33/34    An unfortunate chance keeps hard strong engineer in hospital in borders of Lee (once part of Kent) (5,5)
    1/8    Raising dead and other things, obi-man was chief after faction’s leader ran away (4,4, one of two words)
    2/7    Outgrowths start to grow out of seaweed; nearby club moss initially fine after being cut off (4,4)
    3/6    1000 kg weight dropped by Newton reconstructed almost entirely in huge hollow in German city (5,5)
    4/5    European Union supports me rearing bird reptile cross - number hatched lacking top of beak (4,4)
    9/11    Fruit one kept in a dirty hogshead one found in mire (4,4)
    17/20    Crocodile from flooded valley, with local girl’s protection, paddled flaccidly and lay heartlessly eating most of coot (6,6)
    18/19    Stale contaminated lake releasing foul gas every so often causes a smoky atmosphere (4,4)
    21/25    Copper giving rise to publicity in court, incriminating author upset about old sweetheart (5,5)
    22/24    Rather short cracked bottle containing hair-powder once used by Boswell - top of it is covered in mould (5,5)
    29/30    Rorqual is heading up around Spain, escaping North, last of an unknown number (3,3)

To enter this competition, send your entry as an image or in list format indicating the highlighted cells,  to before the 8th February 2016.The first correct entry drawn from the hat will receive a book from the Chambers range which has been donated by