When transiting Pluto, the planet of deep change and what has to end so something else can start, lands exactly on your natal Moon, the planet that rules your inner weather and what you need to feel safe, the two act as one thing for the length of the transit. That length is two to three years. Because Pluto turns retrograde every year, it often crosses the exact degree three times, and the effect builds and releases in waves rather than all at once. This is a transit that goes straight to the root of how you feel and react.
Pluto moves round the zodiac in about 248 years, so in a human lifetime it makes this aspect to any one natal point once. That matters. Whatever this transit stirs up, it does not come round again. The Moon is one of the most personal points in a chart, and Pluto working directly on it tends to feel less like an external event and more like something shifting inside that you cannot quite name at first.
Spisce opens this transit when Pluto is within 3 degrees of your natal Moon. If you are using the app and you see it listed, that 3-degree window is already open, which means you are in the early part of it.