A circuit includes a line input for receiving a line power. The circuit further includes a line output for transmitting the line power. The circuit further includes a next-gun-detect output and a next-gun-detect input. The circuit further includes a first detonator connection and a second detonator connection, the second detonator connection being connected to a ground. The line input is coupled to the first detonator connection through a one-polarity-pass component that only allows power of a first polarity to pass. The line input is coupled to the first detonator connection through a detonate-enable switch circuit that is coupled to the next-gun-detect output and the line input. The detonate-enable switch passes power only if (a) the next-gun-detect output is not coupled to the next-gun-detect input and (b) power of a second polarity has previously been applied to the line input while the next-gun-detect output is not coupled to the next-gun-detect input.