The Mandelbaum Gate 3***
Not to Disturb 4****
The Takeover 4****
..... overall, just a bit above 3½***

Note that this series of four omnibus volumes includes all of Spark's novels up to and including The Only Problem (1984), with the later novels available in individual volumes not part of the omnibus series. These omnibus volumes can be slightly pricey – and the third volume seems particularly rare – but Spark-biographer Martin Stannard treats them as the canonical text for the seventeen included novels since these were the last texts published during Spark's lifetime and supervised by her. ( )