Last one 13 down (5,1,5) Ring about dodgy steps as entrances c_s_s/_/s_e_l. I thought may 'casts a spell' with ca ll around steps and a but do not get the wordplay. Help please from 8 time zones away!...
Last clue and I cannot make any headway on it:
25d Otter's refuge - when heated, plunge into lake (4)
_ o_ t ???
An explanation would be appreciated. Thank you...