Barney the disappearing cat

The people who wanted to adopt Barney turned up this morning and as soon as he figured out what was happening he morphed from nice wee purring puss into fiendish Houdini cat-with-claws.   Last seen heading west!      It could have been something to do with the excited dog they had in their car (I ask you).     Anyway, we have promised that if he comes back and if we can capture him, we will take him over.... I doubt it somehow.