Folks: The striker block is a safety backup to the seer. If, for some reason the seer doesn't catch the striker, the striker block ensures that the striker cannot, in any way, move forward and strike the bullet primer. The striker block MUST operate reliably on its own! It cannot rely on an operating control (the seer) to function to set it! If this was the case, then a malfunction seer would mean that the striker block is also not functional. I've owned several S&W striker fired pistols and the Shield Plus is the first one where the striker block relies on the seer to pull the striker back in order to set the striker block. This is not proper in any way and if this is how the striker block is designed to operate (as suggested by others herein) then this is a serious design flaw! I have sent my brand new, never fired, shield plus back to Smith & Wesson asking them to correct this situation on my gun. One other thing to note is that while I was at the gun store discussing this, they pulled their display model to examine it and the striker block wouldn't set even when the striker was manually pulled back!!