  The narrow-line Seyfert 1 galaxy Mrk 335 was one of the X-ray brightest AGN,
but it has systematically faded since 2007. Here, we report the discovery with
Swift of a sequence of bright and rapid X-ray flare events that reveal the
emergence of Mrk 335 from its ultra-deep multiyear low state. Results are based
on our dedicated multiyear monitoring with Swift. Unlike other bright AGN, the
optical-UV is generally not correlated with the X-rays in Mrk 335 on a
timescale of days to months. This fact either implies the absence of a direct
link between the two emission components; or else implies that the observed
X-rays are significantly affected by (dust-free) absorption along our l.o.s.
The UV and optical, however, are closely correlated at the 99.99 percent
confidence level. The UV is leading the optical by delta t = 1.5+/-1.5 d. The
Swift X-ray spectrum shows strong deviations from a single power law in all
brightness states of the outbursts, indicating that significant absorption or
reprocessing is taking place. Mrk 335 displays a softer-when-brighter
variability pattern at intermediate X-ray levels, which has been seen in our
Swift data since 2007 (based on a total of 590 observations). This pattern
breaks down at the highest and lowest count rates. We interpret the 2020
brightening of Mrk 335 as a decrease in column density and covering factor of a
partial-covering absorber along our line of sight in form of a clumpy
accretion-disk wind that reveals an increasing portion of the intrinsic
emission of Mrk 335 from the disk and/or corona region, while the optical
emission-line regions receive a less variable spectral energy distribution.
This then also explains why Mrk 335 was never seen to change its optical
Seyfert type (not 'changing look') despite its factor 50 X-ray variability with
Swift.
